1 Tbsp unsalted butter
3-1/2 cups cake flour (sub--sift 1-3/4 cup flour with 1/4 cup cornstarch)
1/2 cup unsweetened cocoa
1-1/2 tsp salt
2 cups canola oil
2-1/4 cups granulated sugar
3 large eggs
1/2 oz red food coloring
1-1/2 tsp vanilla
1-1/4 cup buttermilk (sub--1 Tbsp white vinegar, add milk to 1 cup line; let sit 5 min.)
2 tsp baking soda
2-1/2 tsp white vinegar
Preheat oven to 350 degrees.
Whisk flour, cocoa, and salt in bowl.
Beat oil and sugar at medium speed until well-blended. Beat in eggs, one at a time. With machine on low, very slowly add red food coloring. Add vanilla. Add flour mixture and buttermilk alternately in two batches.
Place baking soda in a small dish, stir in vinegar and add to batter. Beat 10 seconds.
For 3-level cake: Place tsp of butter in each of 3 round 9-inch cake pans. Place in oven until butter melts. Line with parchment. Divide batter between pans. Bake 40-45 min. Let cool 20 minutes. Remove from pans and cool completely.
For cupcakes: makes about 35 cupcakes. Fill 3/4 of the way. Cook 20-25 minutes.
For mini-cupcakes: makes about 50 or more. Cook about 15 minutes.