• Preheat oven to 350 degrees. Line a 12-tin cupcake pan with cupcake liners.
• Combine cocoa and hot coffee together, stirring until smooth.
• Beat butter with a standing mixer or hand mixer until creamy and fluffy, about 2-3 minutes.
• Gradually add in white and brown sugar, beating 2-3 minutes until it is light and fluffy. Add eggs, 1 at a time, beating just until the yellow disappears.
• Add in chocolate/coffee mixture, and beat until just combined.
• In a bowl, sift together flour, baking soda, baking powder, salt, and espresso powder.
• Stir together buttermilk, vanilla extract, and sour cream.
• Alternately mix the buttermilk mixture and flour mixture with the butter batter, beginning and ending with the flour mixture. Do not overmix.
• Divide batter evenly between muffin cups (the batter makes 14-16).
• Bake for 17-18 minutes, or until a cake tester comes out clean. Be careful not to over-bake, as chocolate cupcakes can get very dry if over-baked.
• Allow to cool.

Vanilla Buttercream

• For the frosting, beat butter until light and fluffy. Add in powdered sugar, a cup at a time starting with only 3 cups. Add in heavy cream, vanilla extract, and a pinch of salt. Beat until light and fluffy, about a minute.
• If the frosting is too thin, add in the other cup of powdered sugar, 1/2 a cup at a time. If it's too thick, add in more heavy cream, a Tbsp at a time.
• Once the cupcakes have cooled, pipe the frosting on. Add sprinkles.
• Enjoy!