This bakery-style gluten free white cake, made without any egg yolks, is the perfect moist and tender blank canvas to dress up for any occasion.
What is a white cake & how do you make it?
A white cake is simply a yellow cake made with only egg whites and no egg yolks. Egg yolks add a more yellow tinge to a vanilla cake and give it more of a custard-like texture.
A white cake is perfect for dressing up with food coloring to make a fancier-looking cake. And it's also a great cake for adding sprinkles, nonpareils, or edible confetti to for a funfetti-style cake. It also makes more of a dramatic presentation than a yellow cake.
But this white cake is not just our very best gluten free yellow cake simply made without any yolks. When I decided to make a white cake, I tried just replacing the whole egg with more egg whites, without changing anything else and it works “okay.” But that cake is generally amazing, and “okay” just isn't good enough!
The batter was really just too thick, and the cake became stale way too quickly. That means it wasn't moist enough to start. An egg yolk is not just a yellow egg white. It has the fat of the egg in it, and fat is a tenderizer in baking.
I tried increasing the amount of sugar in the recipe since sugar is also a tenderizer, but again the batter was too thick. The cake was also too pale for most of the baking time and then browned too much at the end once the sugars caramelized. No good.
Finally, I added more butter (1 more tablespoon of butter per cake, so 2 more tablespoons total in the recipe), and mixed the egg whites into the butter and sugar mixture at the start of the batter. That made a world of difference since it allowed for a vigorous beating of the egg whites without overbeating the cake batter once the flours were added.
For a truly white cake, you'll also want to replace the pure vanilla extract, which is brown in color, with a clear vanilla flavoring. I use McCormick brand clear vanilla flavoring since I trust that their extracts and spices have clear labeling that will indicate anything gluten-containing right there on the label.
Since the price of pure vanilla extract has gone sky high lately, I've been using quite a lot of vanilla flavoring in place of extract, in fact. I also sometimes like to replace some of the clear vanilla with some butter flavoring, which really gives this cake that fresh-from-the-bakery flavor and smell.
A note about the egg whites
I made this cake recipe using egg whites from the carton, and egg whites from organic eggs that I separated myself. I found that the carton egg whites worked just as well as the fresh egg whites, and of course using them was much easier.
The crumb coat
In the photo just above, you'll notice that I have the cakes layered and filled, with a nice thin crumb coat on the top and sides. Whether you're serving a layer cake to your family, the Queen of England, or just yourself, you'll want to begin with a crumb coat.
Once you refrigerate a layer cake with a super thin layer of frosting on the top and sides, the “crumbs” really are sealed in and they won't migrate to the frosting on the outside of the cake. Whether you're making a messy frosting or going for a really smooth finish, crumbs just ruin the effect.
How about that frosting?
I nearly used my recipe for ermine frosting on this cake, since it strikes such a nice balance between lightness and sturdiness. Plus, it's not too sweet. But I do really love Swiss meringue buttercream, so I thought about making that, too.
Since this simple recipe took so much recipe-testing to get juuuust right, though, I was too pressed for time to make any sort of multi-step frosting. I started googling an “easier Swiss meringue” frosting, and I stumbled upon this Super Easy Swiss Meringue Buttercream. There's no heating of the egg whites, and no beating them separately, either.
The SugarHero recipe linked above begins with a mix of pasteurized egg whites (from a carton) and confectioners' sugar. Then, you add softened butter and vanilla, and beat the heck out of it.
I made absolutely no changes to the recipe, as it's perfect as written. It's a bit lighter and less achingly sweet than a traditional buttercream, but it was still so easy to make.
Ingredients and substitutions
This is actually a rather simple recipe, and it relies heavily on dairy (butter; buttermilk) and eggs (6 egg whites!). If you make any changes, you are going to have a different cake. Here is the best advice I can give you, but you'll have to experiment as I haven't made the cake successfully with any substitutions:
Dairy/Butter: For a white cake, for appearances, it's better to use Spectrum nonhydrogenated vegetable shortening in place of butter, since it's pure white in color. However, shortening does not have any moisture, and butter has some moisture.
If you'd like to replace the butter in this cake recipe with shortening, I'd recommend using butter-flavored Spectrum shortening as a substitute by weight (that would mean 14 tablespoons, since shortening weighs less than butter).
Watch the video, though, and pay particular attention to the appearance of the batter. I think you'll need to add more buttermilk (I'd say about 1 1/2 tablespoons?) to get the proper consistency but go slowly. Speaking of buttermilk…
Dairy/Buttermilk: I don't like “souring” regular milk (or almond milk) with some lemon juice or another acid as a buttermilk substitute since it doesn't truly sour the milk. Plus, buttermilk is considerably thicker than regular milk.
Instead, if I don't have buttermilk on hand (which I often don't), I like to use whole milk (or for nondairy, unsweetened almond milk or cashew milk) in place of half the volume called for in the recipe. For the other half, I use plain whole milk yogurt (or plain nondairy yogurt). Whisk well, and you've got a perfect replica for buttermilk.
Egg-free: Since this recipe only calls for egg whites, and they're not beaten until stiff like in a meringue, I think aquafaba (the brine from a can of no-salt-added garbanzo beans/chickpeas) would make a seamless substitute for the egg whites in the cake.
I think aquafaba would also work in the frosting recipe, but it will definitely call for some experimentation on your part.
Corn-free: If you can't have corn, try replacing the cornstarch with arrowroot or potato starch, by weight.
A quick note about sifting flours
Okay, yes, you really do have to sift the flour with the cornstarch and the baking powder and baking soda. I hate to sift, and I rarely do it. But it makes an enormous difference in the final baked cake.
If you watch the video, you'll see that I used a sifter. It's this fast-and-efficient sifter from OXO (affiliate link, but shop around) and it's been worth having.