Let’s go way-old-school with a classic American frosting for your lovely homemade vintage cake! This old-fashioned heirloom vanilla custard frosting has a super delicate-smooth texture with a light and lovely sweetness factor. Not overly sweet and not heavy in the least. And it’s so fun to try! Did I mention it uses regular sugar instead of powdered sugar? And I’m going to teach you how to make very simple rose swirls with it. Yay! So, just for a moment, consider dropping the powder plan and grabbing a cup of sugar to test out a frosting alternative from the history files. It’s the key to something way cool.
Have a cup of sugar in your cupboard?: BTW, you’re gonna be BEGGING me for this recipe when you haven’t showered, the traffic is a mess outside, the weather is the pits or you’re all holed up in your cozy kitchen and you do NOT want to run to the market for a box of powdered sugar. (And don’t even THINK about spoiling your lovely homemade cupcakes or cakes with a pre-prepared can of frosting!) To the rescue — “heirloom frosting” with just a cup of granulated sugar. Yes, I said grrrainy granulated sugar.
Add-ons in powdered sugar: Powdered sugar is a staple in modern cake frosting. I use it a lot ’cause it’s a wonderful fluffy white powder sugar that works well for icings and frostings. In terms of sugar history, it is possible that the Italians first began to powder up their sugar by at least the 13th Century. But powdered sugar has evolved over the Centuries. Did you know that powdered sugar has some interesting added ingredients nowadays? Not all of the additives (perhaps none of them) are bad, but I think most folks think powdered sugar today is just a fine ground sugar. Actually, modern powdered sugar (aka confectionery sugar or icing sugar) usually contains additives. Most brands contain an “anti-caking agent” as an additive to prevent lumping. Powdered sugar could contain calcium phosphate, cornstarch, wheat flour or sodium aluminosilicate. Also, its more expensive than “regular” sugar (and we would have used a whole pound of it for this quantity of frosting with a resulting much sweeter frosting). This one contains corn starch…(and my doggie, Paddy, wants some). 🙂
Follow Grandma’s Lead: I’m pretty sure my great-grandmother was very well stocked in terms of pantries, since she had to feed the ranch hands as well as her large family. And I’m sure she didn’t keep powdered sugar on hand. So this would have been her go-to custard frosting recipe on special occasions — for a birthday cake or a special Sunday supper celebration with cake. Haven’t you heard an older relative ask: “What do you think we used to use before we had…[fill in the blank]?
My grandma Margaret reminded me that they used a piece of paper for a dust pan before they owned a dust pan. My great-grandmother plucked a straw from a kitchen broom to test her cakes instead of using a toothpick. So even though we wouldn’t dare go back to basics on most things, sometimes a step back in time brings rewarding results!
Tools Needed for Heirloom Vanilla Custard Frosting:
Small sauce pot
Fork or spoon or heavy whisk (for stirring the custard)
Large Bowl
Electric mixer
Spatula, measuring cups and spoons, spoon or fork
Ingredients for Heirloom Vanilla Custard Frosting:
Double this recipe if you have a 2 layer cake (and want to frost center layer, top and sides) or if you want extra frosting for rose swirls.
1 cup milk (2% is fine)
4 Tablespoons cornstarch (substitute flour in a pinch)
1 cup (2 cubes) unsalted butter, room temperature, cut into cubes
1 cup granulated sugar (not powdered, but regular ole’ sugar)
1 teaspoon pure vanilla extract, fine quality (use “white or clear vanilla extract for really white frosting but sacrifice a bit on flavor perhaps
Okay, let’s rock this simple custard! If you’re sick of sickeningly sweet frosting and if you want to rediscover an historic alternative, let’s do some rediscovering. It’s cake party time!
Directions for Heirloom Vanilla Custard Frosting: It starts with a little milk and some cornstarch in a little pot. We’re starting with the custard step because, even though the next step takes longer, this custard needs to cool to room temperature. So here we go. It’s fun! Remember to double this recipe for a 2 layer cake or extra frosting on a large bundt or tube pan cake.
In a small sauce pot, bring to a very low boil for about 1 minute, stirring constantly with a spoon or fork or heavy whisk:
1 cup low-fat milk (2% is fine)
4 Tablespoons cornstarch
Tip: The milk and cornstarch starts out quite foamy but it will very quickly thicken so be sure you’re on the watch for this reaction and stir it constantly for just a minute to ensure the mixture is cooked and doesn’t burn. If it seems a little lump, then stir quickly to smooth it out.
Now let the custard cool to about room temperature, stirring every few minutes to help bring down the temperature and also keep the custard nice and smooth. Cooling and stirring is an important step to ensure a smooth custard and to keep your precious frosting from melting. You don’t want this custard hot or even warm when you add it to the butter-sugar mixture. Towards the end of the cooling process the custard will thicken even more (so if you’re using a regular whisk, that won’t cut it, unless you use a heavy duty whisk) ’cause it will become very thick.
In an electric mixer, beat on high for about 3 minutes:
1 cup (2 cubes) unsalted butter, room temperature
1 cup granulated sugar (the simple star of the show)
1 teaspoon pure vanilla extract, fine quality (substitute white or clear vanilla extract for a whiter frosting, but sacrifice a bit on taste)
On high-speed, beat into the creamed butter-sugar mixture for about 8 minutes:
the room temperature thick custard (test it to be sure it is not warm)
Tip: A long beating time is necessary to ensure a lovely delicate smooth texture to this old-fashioned granulated sugar frosting.
Double tip: If for any reason your frosting does not look or feel as thick as you’d like, refrigerate it, even overnight if you like, and just let it “thaw” to your desired spreading consistency. Remember, it is loaded with butter — and butter firms when chilled. Also, if you feel the frosting is too thick to spread, leaving it out for a bit on the counter will soften it. Match the photos with your frosting to be sure you’re on the right track.
Okay! Let’s frost this puppy in darling rose swirls and top the cake with a center top filling of fresh berries!
We’re frosting the special Boston Cake made from an 1850 recipe that is loaded with buttery goodness and a little sherry.
We’re going to use a “Star Tip” to create lovely roses for a festive vintage party cake. It doesn’t come with the tip kit (it doesn’t fit in the tip kit) but it only costs a couple of bucks. I just set it in the center of the kit to show how much bigger it is.
Here’s a sideview comparison to show how much larger the 1M Star Tip is…
Using a large star tip, load the whipped custard frosting into a large piping bag (aka pastry bag). I usually use a large reusable pastry bag (’cause larger is easier for me and its simple to clean). Or just cut the tip from the corner of a large plastic baggie and insert the tip into the hole as shown here…
Holding the tip perpendicular to the cake, keep your wrist stiff and make a swirling circle with your whole hand without moving your wrist. If you mess up, just remove the rose with a knife and start over. Keep adding roses of various sizes and shapes until the cake sides and top edges are covered.
Here’s a close up of a rose without the directional arrows…It’s not perfect, but, heck, it’s cute, right?
Fill the top center of the cake with fresh berries that have been tossed with a tablespoon of berry jam (that has a little water to thin the consistency if necessary).
There you have it! A wonderland of vintage roses for your lovely vintage cake! Be sure to check out Miss Leslie’s 1850 Boston Cake for the full cake recipe step-by-step.
Thank you for joining me in my kitchen for a little frosting history adventure. I hope you’re able to try it out soon. Let me know how it goes. I hope to add a little video clip showing the rose swirl action. So watch this post for updates.
Hope to see you on Instagram and Pinterest and Facebook where we’re having fun in the midnight hours sharing photos.
Happy vintage cake baking to you!
Leslie
Related articles you may enjoy:
Mrs. Lincoln’s New and Improved Vanilla Almond Pound Cake (bakethiscake.com)
Fresh Banana Frosting (bakethiscake.com)
Dark Banana Bread (bakethisbread.com)
Homemade Maraschino Cherries (bakethiscake.com)
Bake This Cake! 
Hi Leslie I’ve made frosting using flour (Ermine) and love it, so what are some of the differences that the cornstarch would make (ie: taste, stability)? Thank you!
I’m wondering if merengue powder can be added to give the buttercream some stability in warmer weather? Our wedding is coming up in June and I’ll be baking our wedding cake. I love this recipe and am planning to use it for our wedding cake. Have you an experience adding merengue?
Hi, Monica, Congratulations on your upcoming wedding! As to your Q, truth is, I’ve tested meringue powder a number of times and I just can’t get over that I can taste what seems like a slight chemical flavor but check out Italian Buttercream recipes for perhaps a more stable frosting for warmer weather. Also, there are some additives, like Clear Gel, that I haven’t tried but are said to be helpful. King Arthur Flour ran some tests on melting frosting you can check out here: https://blog.kingarthurflour.com/2018/08/17/best-cake-frosting-hot-weather/ Happy wedding and happy cake baking! Leslie
Thank you for this advice. I will try the Italian recipe. If it’s half as good as the Heirloom recipe, I’ll give it a go.
I’ve been making this kind of icing for years like my mom taught me. I do use half shortening instead of all butter. For my coconut cakes, I substitute half of the regular milk with coconut milk and add some coconut extract in. It has more lumps but I just strain them out before cooling. My friends all love it!
Suzan, Sounds great! Thanks for your tips. Sounds great!! Happy vintage cake baking to you! Leslie
Truly confused by the “cube” description used for the butter. A cube is very specific geometric shape in which all sides are equal. Picture a cube of sugar. A stick of butter is not that. A stick of butter is a stick. You could also just say a cup of butter which many people would understand as two sticks of butter But a “cube” of butter has never been a recognized measure and, well makes no sense at all for anyone who has cooked for more than five minutes. Ever. Thank you.
1/2 cup. Thanks for your comment.
What? No. One cup. One cup is equal to two sticks of butter. Says so right on the side of the stick of butter.
That’s correct, Portia. 2 cubes equals 1 cup. I thought you were asking for the measurement of 1 cube, which is equal to 1/2 cup. Have a great day and thank you for your comments.
This is also known as Ermine frosting, I love it too. One tip I have found is to mix the milk and flour/corn starch while cold and add sugar as well, then bring to slow boil, cool and then add to well beaten butter, table spoon at a time.
I need to make a cake a week ahead of time due to I will be out of town when it is due. Would this frosting hold up to freezing and then thawing?
Is it more of a whipped topping texture???
I haven’t stored s frosting for a week but if I had to in a pinch I would try putting it in a plastic bag prepared to pipe it out then let it sit on the counter a bit or manipulate with my fingers prior to squeezing it onto the cake. This is a pretty hardy custard style frosting so it just might work. Let us know how it goes.
Do you think it’d hold up if the cake was completely decorated and froze?
Hi Mel, I’m not sure how to freeze a frosted cake. I know the cake layers can be well wrapped and frozen but I fear freezing all together with the frosting and decorations may not go well. But, heck, if there’s no other option, what are you to do? Perhaps our pro baker readers might add some comments. Best of luck!
So, is it 1 cup plus 2 cubes of butter?
1 cup. (1 cup of butter is often described as 2 cubes because most cubes are equal to 1/2 cup each. ) Hope that helps.
Thought this recipe sounded like it would be great to go with my salted caramel cupcakes. I’m not going to lie, I got a little worried as I was mixing the butter/sugar mix and stirring the custard individually, but once I mixed them it was magic. This frosting is phenomenal! Thank you so much for sharing!!
Tara, I like that word, magic, to describe this old-fashioned custard frosting. So glad you like it. (And next time you run out of powdered sugar for a “regular” sweet frosting, it just might be a lifesaver.) 🙂 Leslie
Love this stuff it’s pretty much German buttercream.
Hi, can i use this frosting under fondant?
Hi, Maureen! I will readily admit that, although I’ve made homemade fondant, I am not a fondant pro — so, although I can’t see why this vanilla custard frosting wouldn’t be perfect underneath a fondant, I haven’t tried it so I’m not sure. The traditional buttercream is the most common frosting underneath fondant but I think this might be even better (maybe because it is my favorite frosting). Let us know how it goes.
I just finished making this recipe. It came out perfect! This is absolutely delicious, light, not too sweet, it is everything a frosting should be and more. I can not thank you enough!
That makes me very happy! So glad you enjoyed the old fashioned custard frosting. It likely makes our grandmas and great grandmas happy too. Leslie
Does this frosted cake need refrigeration?
This frosting is more hearty than regular buttercream so I have left it under a cake plate in a normal temperature room, after slicing, for up to 2 days and it was fine. I’m afraid these cakes never last longer but perhaps other readers can chime in.
This is the lightest and best icing I have ever made. I will be making this ALOT
Thanks so much
Do you know how many cupcakes this will frost?
Hi Darlene, I’m actually not sure about the number of cupcakes this granulated sugar frosting will do up. I’m usually frosting cakes. Also, some folks like a whole lot of frosting and others don’t. Surely a dozen could be frosted lightly but you might have to double the recipe for adding big rose swirls on top if that’s what you’re looking for. Let us know in the Comments if you have a chance to tell us how many your cupcakes needed. Thanks! Leslie
I made 40 cupcakes with a doubt let [double] batch. I did a double bag of pink and white turned out beautiful 😊
I just tried this recipe and it is just absolutely wonderful! I can’t wait to share this with my mom! I made chocolate cake an opened my cupboard to find that I am out of powdered sugar and came across this recipe after searching for alternatives. This is even better than what I had hoped for! I used almond extract instead of the vanilla. I think for christmas I’ll try a nice rum frosting next! Thank you! You made this hungry and very pregnant woman a happy gal! 🙂
Hi Mariah, Congratulations seem to be in order. I’m so glad you got to try the old-fashioned custard frosting. I know, right? Who ever always has powdered sugar in the cupboard when it turns out to be cake baking time? I’m glad it worked out. I love your idea about adding almond flavoring. Sounds awesome! And a nice rum frosting sounds so yummy. Happy holidays! Leslie
I made this for a carrot cake (taking to a party where some don’t like a cream cheese or sweet icing). It’s seriously wonderful. Very simple, on hand ingredients, very easy to work with. Thank you so much!
Great idea to use this custard frosting for carrot cake! Thank you for letting us know that it worked well for you and with on-hand ingredients! My favorite way to bake – with whatever’s in the cupboard! If you run out of flour, you’ll have to check out our bread crumb cake and cookies. 😉 https://bakethiscake.com/2012/12/23/breadcrumb-cake-and-cookies/
This is actually the original carrot cake frosting☺
Love this! I adapted this to be dairy free and I shared on my blog at mommybusiness.net and Allergymom.tumblr.com
Thanks!
M 🙂
Hi Melissa, I love your allergy-free adapation of this recipe! Nice work! 🙂
Approximately how many cupcakes could I frost with this recipe? Wanted to try this for my niece’s wedding shower. Thanks!!
This is a great little frosting for cupcakes but it doesn’t result in a large batch. I would recommend testing at this quantity first. You might have to quadruple or more depending on your quantity and thickness.
I was raised on cakes with this frosting made by my Czech grandmother. I learned to make it myself when I was 7 years old, after watching/ help make it with gramma. I’m amazed that so many have never discovered this amazing frosting( also delicious as chocolate- add half cup unsweetened cocoa powder & 1/4 tsp salt with sugar). Love it!
Hi Ed! I love hearing about your childhood at grandmother’s side baking cakes and frosting them up. Those are the kind of memories that enrich a child’s life and I’m so happy to hear that you hold those memories so fondly. I’m going to try your cocoa addition. Sounds heavenly. Best regards, Leslie
I am making this right now,as the custard is cooling. Will this hold up in the fridge when I am done? Thank you
Hi, Linda, Because this is a hearty little frosting it should hold well for a number of days properly sealed in the refrigerator (although I usually frost cakes immediately upon cool-down of the cake). I think it might have to sit on the counter to come close to room temperature before frosting. Let us know how it goes if you’re able. Best, Leslie
Love this frosting! it really is a beautiful recipe. My little boy loves it! I would like to use this frosting to pipe my 3 year old’s Thomas the train birthday cake. Do you know if I used coloring jel will the frosting still be firm enough to pipe the cake? Also how long can this frosting prepared stay in the fridge and can I freeze it too?
Hi, Laura, Happy birthday to your Thomas train fan. I use gel colorings with this frosting and they work great, however, my colors are usually on the subtle side and I haven’t tried a large amount of gel for deep colors (I think Thomas Train is bright blue and even some black). Can you try a little test in advance? Good luck! Leslie
Tried this. Absolutely amazing. Very light, but sturdy with a delicate flavor. Not overpowering or sticky sweet.
Hi, Brianna! So glad you enjoyed this old-fashioned recipe. I guess this type of custard frosting has passed the test of time. Happy New Year to you! Leslie
Will this frosting hold up during transport & being refrigerated overnight & then set out for a party? I am making a baby reveal cake and I am delivering it the day before. They requested a “less sweet” frosting and this one sounds great.
Hi Tracie! How fun to do a baby reveal cake. Love that idea. This is a very stable & hearty frosting with a light and smooth sweetness and I think it would do well for your event, however, I always think a test is best beforehand so you know how it works for you. So I hope you can try even a super small batch first before the big event. Keep us posted.
What a great frosting recipe! And I love the roses. So pretty!
Your rose frosting is absolutely gorgeous! I love the sugar history lesson as well.
Thank you, Cathy! Agave & honey testing coming up soon. 🙂
Reblogged this on What's For Dinner? and commented:
Dessert anyone? Got to give this one a try soon!
Lovely and yum! Will be reblogging this one!
Thank you Cathy! So glad you like! 🙂