2. Grease & Flour the Pans
You will need three 9x2-inch or three 8x2-inch round cake pans. To grease and flour the pans, use a paper towel or pastry brush to evenly spread shortening or butter (or nonstick cooking spray) on the bottom, corners, and 1 inch up the sides of the pan. Sprinkle a little flour into the pan; tap the pan so the flour covers all greased surfaces. Tap out any extra flour into the sink. If desired, cut waxed paper to fit the bottom of the pans and place it in the pans after greasing and flouring. This ensures that the cakes will release from the pan without sticking.
Tip: You can also use one 13x9x2-inch baking pan in place of the three round pans.
3. Beat the Batter
- In a very large bowl beat the 3/4 cup softened butter with an electric mixer on medium to high speed for 30 seconds. Gradually add 2-1/4 cups sugar, about 1/4 cup at time, beating on medium speed until well combined. Using a rubber spatula, scrape the sides of the bowl and beat on medium speed for 2 minutes more. Adding the sugar in small additions makes it easier to incorporate more air into the mixture.
- Add the 3 eggs, one at a time, beating well after each addition.
Tip: To prevent the possibility of getting eggshell in the cake batter, break each egg into a custard cup before adding. If any shell is in the cup, remove it with a spoon before adding the egg to the batter.
- Carefully beat in a 1-ounce bottle (2 tablespoons) red food coloring and 1-1/2 teaspoons vanilla. This may seem like a lot of food coloring but it takes that much to provide the stunning red color.
- Alternately add the flour-cocoa mixture from Step 1 with 1-1/2 cups buttermilk (see tip below about a sour milk option), beating on low speed after each addition just until combined, and beginning and ending with the flour-cocoa mixture. Do not overmix at this stage, as this can cause elongated, irregular holes in the finished cake.
Tip: If you don't have buttermilk, you can also use sour milk. To make sour milk, place 4-1/2 teaspoons vinegar in a 2-cup glass measuring cup. Add enough milk to make 1-1/2 cups total liquid. Let the mixture stand for 5 minutes before using it.
- In a small bowl combine 1-1/2 teaspoons baking soda and 1-1/2 teaspoons vinegar and gently stir it into the batter. Pour batter into the prepared pans, dividing it evenly. Use an offset metal spatula to spread the batter in an even layer. Be sure to spread the batter to the edges of the pan.
4. Bake the Cake
- Bake until a toothpick inserted near the centers comes out clean, using the times listed below as a guide and checking the cakes at the minimum baking time.
— For 9-inch pans, bake for 20 to 25 minutes.
— For 8-inch pans, bake for 25 to 30 minutes.
— For a 13x9x2-inch pan, bake for 30 to 35 minutes.
- Cool cake in the pans on wire racks for 10 minutes. For cake layers, place a wire rack over the top of the cake and flip the cake and pan. Lift the pan off the cake, being careful not to tear the edges of the cake. If using, gently peel the waxed paper off the cake. Cool completely on racks. For a 13x9x2-inch cake, do not invert. Instead, place the cake in the pan on a wire rack and cool completely.
Tip: To freeze unfrosted cake layers, place the cooled cake layers on a baking sheet and freeze until firm. Transfer the cake layers to large freezer bags or wrap and seal in freezer wrap. Freeze for up to 4 months. Thaw before frosting.
5. Make the Buttercream Frosting
This buttery frosting starts with a white sauce that is sweetened with sugar and cooked. It yields 4 cups frosting. If making a 13x9x2-inch cake, cut the frosting recipe in half.
- Allow 1-1/2 cups (3 sticks) butter to stand at room temperature for 30 minutes to soften.
- In a medium saucepan whisk together 1-1/2 cups sugar, 1-1/2 cups milk, 1/3 cup all-purpose flour, and a dash salt. Cook and stir over medium heat until thickened and bubbly. Reduce heat to low; cook and stir for 1 minute more. Remove the pan from the heat. Stir in 1-1/2 teaspoons vanilla. Cover the pan and cool completely at room temperature.
- Once cooled, transfer the mixture to a large bowl. Using an electric mixer on medium speed, gradually beat in the softened butter until the mixture is smooth, scraping sides of bowl occasionally.
Tip: The frosting might look curdled until all of the butter is incorporated.
6. Assemble & Frost the Cake
- For layer cakes, place one cake layer, bottom side up, on a serving plate. Spread with one-third of the frosting. Top with the second layer, bottom side up; spread with one-third of the frosting. Top with the third layer, top side up. Spread the top with the remaining frosting.
- For the 13x9x2-inch cake, spread the halved frosting recipe over the top of the cooled cake in the pan.
- You can serve the frosted cake right away or cover it loosely with foil, plastic wrap, or a cake cover and store in the refrigerator for up to 3 days. Before serving, let the cake stand at room temperature for 30 to 60 minutes or until the frosting is softened.