ingredients

2 2/3 cups cake flour
1 1/2 tsp baking powder
1/2 tsp salt
1 stick salted butter, room temperature
1 stick unsalted butter, room temperature
2 cups granulated sugar
4 egg whites
2 tbsp vanilla paste (my favorite, but you can use vanilla extract if you don’t have paste – but really, i think the paste makes the cake, so buy it ahead of time or order on amazon)
1 cup buttermilk (or whole milk)
>also: see tips section for how to make your own buttermilk in a pinch.

buttercream frosting
2 sticks salted butter, room temperature
4-6 cups powdered sugar
3 tsp vanilla paste (or extract)
2-3 tbsp milk or half + half

directions

1. preheat oven to 350.
butter & flour two 8-inch round cake pans.

2. in a large bowl whisk together flour, baking powder, and salt.

3. in another large deep bowl or the bowl of an electric stand mixer, beat butter until light and fluffy, about 4 to 5 minutes. scrape the sides and the bottom of the bowl halfway through.

add sugar 1 cup at a time and beat on high speed until light and fluffy. scrape sides & bottom.

on low speed, mix in egg whites and vanilla, then beat on high until thick and smooth.

4. add half of the flour mixture and beat on low speed until almost incorporated. add the buttermilk and blend together. add the rest of the flour mixture and beat until almost incorporated.
remove bowl from mixture (or set aside hand mixer) and finish blending the ingredients with a spatula.divide the batter between the two cake pans.

give the pans a couple of taps on the counter to deflate any air pockets in the batter.

5. bake for 25 to 27 minutes, until golden brown and a skewer inserted in the center comes out clean.
remove from the oven and let cool on wire racks. allow to cool completely before frosting.

for the frosting:
when i am making frosting, it is more of a loose recipe..
put out butter on the kitchen counter to come to room temperature at least 3-4 hours in advance. once the sticks are at room temp, place them in the bowl of a mixer or a deep mixing bowl. beat until light and fluffy. add 1 cup of powdered sugar. beat well. and 1 more cup and beat well. add vanilla and milk (or half + half). add 1 cup powdered sugar and beat well. repeat once more. then repeat as necessary to get to the consistency you like for your frosting.