Use this recipe to make Mint Chocolate-Chip Cake and Swirly Cupcakes.
Heat oven to 325 degrees. Butter two 8-inch-square baking pans. Line with parchment, and butter again. Flour pans, tapping out excess; set aside.
In the bowl of an electric mixer fitted with the whisk attachment, combine all the ingredients except the hot coffee. Mix ingredients on low speed until combined, about 1 minute. Slowly add the coffee. Mix until smooth, about 1 minute. Pour batter into prepared pans; smooth tops with an offset spatula.
Bake until a cake tester inserted into the middle comes out clean, 25 to 30 minutes. Transfer the pans to wire rack to cool. Turn out the cakes, and wrap them in plastic wrap until ready to use.
Milk may be substituted for the coffee.