Becca's Birthday Cake

It was my boo's birthday this week (the big 26!), and I knew this cake had to be the best. It's a riff on a classic white birthday cake, dressed up with some fancy white chocolate frosting and a lemon buttercream filling. If lemon's not your thing, I've included a couple of alternative filling options down in the notes section. Happily, this cake can be customized to fit your birthday haver's preferences with very minimal effort. 

Note: this makes a three-layer cake. It will be impressive, and it will be large. You will need to buy two packages of butter. You can scale it down for two 9-inch layers if you just don't feel like you really need that much cake (but hey, where's the fun in that?), just reduce each ingredient by a third.

Becca's Birthday Cake

Yield: 14-16 slices - this depends on you ;)

Total cook time: 2 hours


Birthday Cake

  • Unsalted Butter (room temperature): 1 1/2 cups (3 sticks)
  • Granulated Sugar: 2 1/4 cups (510 grams)
  • Salt: 1 1/2 teaspoons (9 grams)
  • Egg Whites (Large): 6
  • Buttermilk: 1 1/2 cups (360 mL)
  • Vanilla Extract: 2 teaspoons
  • Corn Starch: 1/4 cup (48 grams)
  • Baking Powder: 3 teaspoons
  • Flour: 3 cups (390 grams)
  • Lemon Zest: 1 teaspoon (Optional)

Lemon Buttercream Filling

  • Unsalted Butter (Room Temperature): 1 cup (2 sticks)
  • Powdered Sugar: 4 1/2 cups
  • Vanilla Extract: 1/2 teaspoon
  • Heavy Cream: 2 tablespoons
  • Lemon Juice: 2 tablespoons
  • Lemon Zest: 2 teaspoons
  • Salt: Tiny pinch

White Chocolate Frosting

  • Unsalted Butter (Room Temperature): 1 cup (2 sticks)
  • White Chocolate (Chopped or in Chip Form): 12 ounces
  • Vanilla Extract: 1 teaspoon
  • Salt: Tiny pinch
  • Powdered Sugar: 1 cup


A Few Notes: 

  • Don't want to use corn starch? No prob, swap the regular flour for cake flour and ditch the starch.  

  • In a rush? You can hurry the cooling down process by popping the cakes (cooling rack and all) in the freezer.

  • I added a teaspoon of lemon zest to the cake itself - highly recommended.

  • Lemon isn't your thing? Skip the lemon zest + juice in the buttercream, but add another teaspoon of vanilla extract.

  • Want to take this cake to the next level? Add a thin layer of jam over the lemon filling (I suggest strawberry or raspberry).

  • I find it's much easier to frost cakes when they're cold - try popping the layers in the fridge while you're making the frosting.

  • Need to make this ahead of time? Make the cake layers, then wrap them separately in plastic wrap and freeze (up to a week). Frosting is best the day it's made. 

  • Want a funfetti cake? Gently fold in 1/2 cup of sprinkles (I find that the plain old long rainbow jimmy's hold their color the best) into your batter after you add the flour.


Pairs Well With: 



*Special Equipment: Three 9-inch cake pans

The How To (Birthday Cake):

Preheat your oven to 350 degrees F and line three 9-inch cake pans with parchment paper. Butter the parchment paper and sides of the pans. Beat the butter, sugar, and salt in the bowl of a stand mixer on medium speed until light and slightly fluffy (about 3 minutes). Add the egg whites, a bit at a time - beat until fluffy. Beat in the vanilla and buttermilk. Add the baking powder and the corn starch (& lemon zest, if using). Beat until thoroughly incorporated, then beat some more. Add the flour in one burst - mix on low speed just until combined. 

Pour into prepared pans. Bake at 350 degrees for 20-22 minutes, or until golden and a toothpick inserted into the middle of the cake comes out clean. My oven doesn't fit three 9-inch pans at once, so I did my baking in two batches. Let the cakes cool in the pans for 5 minutes, then turn them out onto a cooling rack to cool completely. 

The How To (Lemon Buttercream Filling):

In the bowl of a stand mixer, beat the softened butter until creamy. Gradually add the powdered sugar (a cup at a time), then beat until light and very fluffy (about 3 minutes). Scrape down the bowl. Add the vanilla extract, lemon juice, lemon zest, and salt - beat until fully incorporated. Beat in the heavy cream. Set the frosting aside (I put mine in a pastry bag) and wipe out the bowl to prepare for the white chocolate frosting!

The How To (White Chocolate Frosting):

Melt your white chocolate - you can do this by putting it in a heat safe bowl and microwaving in short spurts, or by placing a heat safe bowl over a bowl of simmering water and stirring until melted. Set aside until slightly cooled. In the bowl of a stand mixer, beat the butter until creamy. Add the white chocolate and beat on medium speed until slightly fluffy. Add the powdered sugar, vanilla extract, and salt. Beat on medium speed until very fluffy. Taste test for quality control ;) 

The How To (Assembly):

Trim any domed tops of the layers with a serrated knife. Alternate cake and lemon buttercream layers - I like to use a piping bag with a large round tip to pipe in the filling in a spiral shape and then smooth it with a offset spatula (this ensures that you'll have that lovely thick layer of frosting between the layers that's so photogenic). A Ziploc bag with the end cut off will also work for this! Frost the top and outside of the cake with your white chocolate frosting. Decorate as you see fit. After adding an imperfect layer of frosting to the outside of my cake, I dragged an offset spatula from the bottom to the top of the cake (in rows) to get those rustic lines. 

Add candles. Sing happy birthday. Act surprised when they're actually trick candles. Eat cake.