Ingredients
1½cupscake flour,spoon and leveled
1tspbaking powder
¼tspBaking Soda
½tspsalt
6tbspunsalted butter,softened to room temperature
¾cupgranulated sugar
2large egg whites,at room temperature
⅓cupsour cream,or full fat plain yogurt, at room temperature
1tsppure vanilla extract
⅓cupwhole milk,at room temperature
½cupsprinkles
¾cupunsalted butter,softened to room temperature
3cupsconfectioners’ sugar
3tbspheavy cream,or half-and-half, whole milk, at room temperature
1tsppure vanilla extract
salt,to taste
sprinkles,for garnish, optional
Preparation
Preheat oven to 350 degrees F. Grease a 9×2 inch round cake pan, line with a parchment paper round then grease the parchment paper. Parchment paper helps the cake seamlessly release from the pan.
Whisk the cake flour, baking powder, baking soda, and salt together. Set aside.
Using a handheld or stand mixer fitted with a paddle or whisk attachment, beat the butter on high speed for about 1 minute until smooth and creamy. Add the sugar and beat on high speed for about 1 minute until creamed together. Scrape down the sides and up the bottom of the bowl with a rubber spatula as needed.
On high speed, beat in the egg whites until combined, then beat in the sour cream and vanilla extract. Scrape down the sides and up the bottom of the bowl as needed.
Pour the dry ingredients into the wet ingredients. Turn the mixer to low speed and as the mixer runs, slowly pour in the milk. Beat on low speed just until all of the ingredients are combined. Do not over-mix. The batter will be slightly thick. Gently fold in the sprinkles.
Pour batter evenly into prepared cake pan.
Bake for about 27 to 31 minutes or until the cake is baked through. After about 18 minutes, tent the cake with aluminum foil to prevent the top and edges from over-browning. To test the cake for doneness, insert a toothpick into the center of the cake. If it comes out clean, it’s done.
Allow cake to cool completely in the pan set on a wire rack. The cake must be completely cool before frosting.
With a handheld or stand mixer fitted with a paddle attachment, beat the butter on medium speed for about 1 minute until creamy. Add the confectioners’ sugar, heavy cream, and vanilla extract. Beat on low speed for 30 seconds, then increase to medium-high speed and beat for 2 full minutes.
Add up to ¼ cup of confectioners’ sugar if frosting is too thin or a splash of heavy cream if frosting is too thick. Add a pinch of salt if the frosting is too sweet.
Spread frosting all over the top. Top with sprinkles, if desired.
