01 -
Heat oven to 350°F. Line three 8-inch pans.
02 -
Mix dry ingredients in stand mixer.
03 -
Mix in butter until sandy.
04 -
Add egg whites, then buttermilk gradually.
05 -
Mix in oil and vanilla.
06 -
Beat at medium speed for 1 minute.
07 -
Divide the batter between pans.
08 -
Bake for 33-35 minutes.
09 -
Cool for 10 minutes, then freeze for 30 minutes.
10 -
Beat butter until smooth.
11 -
Add vanilla and salt.
12 -
Gradually add powdered sugar and heavy cream.
13 -
Beat until smooth.
14 -
Level the cooled cake layers.
15 -
Stack layers with buttercream between.
16 -
Crumb coat the cake and chill.
17 -
Apply final coat and decorate as desired.