Ingredients:

  • 1 standard box Yellow or Chocolate Cake Mix (15.25 oz size)
  • 1 cup Whole Milk (or Buttermilk, for cake batter)
  • 1/2 cup Unsalted Butter, melted (for cake batter)
  • 4 large Eggs (for cake batter)
  • 1 teaspoon High Quality Vanilla Extract (for cake batter)
  • 1 teaspoon Espresso Powder (optional, for chocolate cake)
  • 1 cup Unsalted Butter, softened (for frosting)
  • 4 cups Powdered Sugar, sifted (for frosting)
  • 4-6 tablespoons Heavy Cream or Whole Milk (for frosting)
  • 1 1/2 teaspoons Vanilla Extract (for frosting)
  • 1/4 teaspoon Salt (for frosting)

Instructions:

  1. Preheat oven to the temperature specified on the box. Grease and flour two 9-inch round cake pans, or line bottoms with parchment paper rounds.
  2. In a large bowl, whisk together the whole milk, melted butter, extra eggs, and vanilla extract until well combined.
  3. Add the entire box of dry cake mix to the wet ingredients. Mix on low speed with an electric mixer until just combined (about 30 seconds).
  4. Increase speed to medium and beat for precisely 2 minutes. If using espresso powder, gently stir it in by hand now.
  5. Divide batter evenly between prepared pans. Bake according to package directions, testing for doneness 3 minutes before the minimum time listed (toothpick should come out clean or with moist crumbs).
  6. Let cakes cool in pans for 10 minutes before inverting onto a wire rack to cool completely. Do not frost warm cakes.
  7. For the frosting: Beat the softened butter in a stand mixer until very pale and fluffy (about 3 minutes).
  8. With the mixer on low speed, gradually add the sifted powdered sugar, one cup at a time, scraping down the bowl between additions.
  9. Add the vanilla, salt, and 4 tablespoons of heavy cream/milk. Beat on medium-high speed for 3–5 minutes until the frosting is lightened in color and texture. Add remaining liquid only if needed for spreadability.
  10. Level the cooled cake layers if necessary. Place the first layer on a serving plate, spread with a generous layer of buttercream, and top with the second layer. Frost the top and sides of the entire cake.