Ingredients:

  • 1 standard box (approx. 15.25 oz / 432g) cake mix
  • 3 large eggs (instead of 2)
  • 1/2 cup melted unsalted butter (instead of oil)
  • 1 cup whole milk or buttermilk (instead of water)
  • 1 teaspoon vanilla extract
  • 1 teaspoon instant espresso powder or strong brewed coffee (optional, for chocolate mix)

Instructions:

  1. Preheat oven according to cake mix box directions (usually 350°F / 175°C). Grease and flour two 8 or 9-inch round cake pans, or line the bottoms with parchment paper.
  2. Melt the 1/2 cup of unsalted butter and let it cool slightly so it doesn't cook the eggs.
  3. In a medium bowl, gently whisk together the 3 eggs, the melted butter, and the milk or buttermilk. If using espresso powder, dissolve it into the milk first. Add the vanilla extract.
  4. Empty the contents of the cake mix into a large mixing bowl.
  5. Pour the wet ingredients into the dry ingredients. Mix on low speed or by hand just until combined. Stop mixing as soon as the last streaks of flour disappear; do not overmix.
  6. Divide the batter evenly between the prepared pans. Bake according to the box instructions, checking for doneness 5 minutes early. The cake is done when a wooden skewer inserted into the centre comes out clean.
  7. Let the cakes cool in the pans on a wire rack for 10–15 minutes. Run a thin knife around the edges, invert onto the rack, and allow them to cool completely before attempting to frost.