Holy Grail birthday cake
serves 10-12
recipe notes: moderate
cake adapted from: Smitten kitchen

FOR THE CAKE:
1 cup salted butter - room temp
1 cup + 1/3 cup sugar
1 teaspoon kosher salt
4 large egg whites
1 tsp vanilla extract
1 cup buttermilk
2 tsp baking powder
4 TBS cornstarch
2 cups all-purpose flour

preheat the oven to 350 F. then line the bottom of two 9-inch round cake pans with parchment paper and coat the bottom and sides with butter.

beat butter, sugar, and salt together in the medium bowl of an electric mixer. add the egg whites, one at a time, beating until combined and fluffy. add the vanilla and buttermilk, then the baking powder and cornstarch and beat until well combined. scrape down sides of bowl and beat once more. finally add the flour and mix just until combined.

bake for 20+ minutes, or until a toothpick inserted into the center of the cake comes out batter-free. allow to cool in pan for 5 minutes, then run a knife around the side to loosen the cake, flip it out and cool completely.

FOR THE FROSTING:
1 pound salted butter - room temp
8 oz of cream cheese - room temp
4 + cups (1 pound) of powdered sugar - sifted

in the bowl of an electric mixer with the paddle attachment, combine the butter and cream cheese; cream together until light and fluffy. finally the sugar one cup at a time.

to frost the cake, place one of the cakes on your cake tray. place a large dollop of frosting on the center of the cake and use a off-set spatula to push the frosting out and around making a smooth layer. then add the next cake on top and do the same, this time adding so much frosting so it can be pushed off the sides to fully frost the sides. use a wet paper towel to clean the cake tray and now you can decorate your cake.