If it lasts more than a few days, refrigerste the leftover cake, but let it come to room temperature before serving so the frosting soft.
Makes 16 servings: Total time about 1 hour = cooling.
SIFT:
1 3/4 cups each all purpose flour and cake flour
1/4 cup unsweetened cocoa powder
1 tsp each baking soda,table salt, and instant espresso powder
BEAT: 2 1/4 cups sugar
3 eggs
2 1/4 cups vegetable oil
COMBINE:
1 2/3 cups buttermilk
2 tbsp liquid red food color (1 oz)
1 tsp vanilla extract
1 tbsp distilled white vinegar
Preheat oven to 375º. Line two 8×2-inch square pans or three 9×2-inch round cake pans with parchment paper and coat with nonstick spray.
Sift together all purpose flour, cake flour, cocoa powder, baking soda, salt, and espresso powder.
Beat sugar and eggs in a separate large bowl with a hand mixer on high speed until white, thick and creamy, 5-7 minutes.
Drizzle in oil with mixer on low speed until fully incorporated.
Combine buttermilk, food color, and vanilla in a large glass measuring cup with a pour spout until throughly blended.
Alternately add flour mixture and buttermilk mixture to batter starting and ending with flour mixture and mix after each addition until combined.
Mix vinegar into batter and divide evenly between prepared pans.
Bake cakes until toothpicks inserted in centers comes out clean, 35-40 minutes.
Let cakes cool on rack 10 minutes, then turn out of pans, cool on racks, and peel away parchment.
Slice cakes in half horizontally to form 4 layers. (for round cakes,slicing not required).
WHITE CHOCOLATE FROSTING
Makes about 5 cups
WHISK:
2 cups whole milk
1 1/2 cups all purpose flour
MELT:
4 oz white bar chocolate,chopped
CREAM:
2 cups sugar
2 sticks unsalted butter, softened
WHISK together milk and flour in a saucepan over medium heat, stirring constantly with a rubber spatula until thick, paste-like and no longer lumpy, 15 minutes. Transfer mixture to a bowl, and press plastic wrap over surface to prevent a skin from forming: chill until cold.
MELT chocolate in a double boiler until smooth, let cool slightly.
CREAM sugar and butter in the bowl of a stand mixer on high speed until light and fluffp, about 7 minutes. Add chilled milk mixture and melted chocolate and beat on high speed until light and fluffy. about 5 minutes more.
For mess free and even frosting between cake layers, pipe it in cocentric liones around the edges.
To add stability to the cake, dowel it by pressing cut skewers all the way into the cake’s corners and center.
Crumble trimmed cake edges into crumbs and sprinkle over top of frosted cake