Preheat oven to 350 degrees and line 24 muffin cups with paper liners.
Combine all the cupcake ingredients (Devil's Food Cake Mix, Butter, Coffee, Eggs) in a mixer until combined. Add in the mini chocolate chips.
Spoon cupcake mixture into paper liners. Don't overfill.
Bake until cupcakes come out clean when a toothpick is inserted in them. About 18-20 minutes.
Move to wire racks and let them cool completely.
For the Buttercream Frosting:
Beat the butter in a mixer at medium speed for about 2 minutes, or until creamy.
Gradually beat in the powdered sugar at low speed.
Beat in vanilla extract.
Increase speed and continue to beat until mixture is light and fluffy.
Gradually beat in heavy whipping cream on low speed.
Increase speed and beat until frosting is light and fluffy again, about 1 minute.
Spread the frosting into a pastry bag and pipe it onto the cooled cupcakes. Decorate cupcakes with candy eyes to make them ghost cupcakes, or Halloween sprinkles as well.