Ingredients
Equipment
Method
- Instructions Preheat the oven to 350°F (177°C). Grease and lightly flour two 9-inch cake pans.Whisk the cake flour, baking powder, baking soda, and salt together. Set aside.Using a handheld or stand mixer fitted with a whisk attachment, beat the butter on high speed until smooth and creamy – about 1 minute. Add the sugar and beat on high speed for 2 minutes until creamed together. Scrape down the sides and up the bottom of the bowl with a rubber spatula as needed. Add the egg whites. Beat on high speed until combined, about 2 minutes. Then beat in the sour cream and vanilla extract. Scrape down the sides and up the bottom of the bowl as needed.With the mixer on low speed, add the dry ingredients until just incorporated.With the mixer still running on low, slowly pour in the milk until combined. Do not overmix. You may need to whisk it all by hand to make sure there are no lumps at the bottom of the bowl. The batter will be slightly thick.Pour batter evenly into cake pans. Bake for around 24-25 minutes or until the cakes are baked through. To test for doneness, insert a toothpick into the center of the cake. If it comes out clean, it is done. Allow cakes to cool completely in the pans set on a wire rack. The cakes must be completely cool before frosting and assembling.