Preheat oven to 350°F (180°C).
Line 3 muffin tins with cupcake liners.
Combine flour, cocoa, sugar, baking powder, salt, and pudding mix in a large bowl (if using an electric mixer), or the bowl of a stand mixer set with a paddle attachment.
Carefully add buttermilk, melted butter, eggs and vanilla to the bowl of dry ingredients, mixing on medium speed until smooth.
Use food colouring to tint batter black.
Divide batter among prepared muffin pans. Bake until knife inserted into center of batter comes out clean - about 20-22 mins .
Allow to cool to cool to room temperature, before decorating.
Prepare either Swiss meringue buttercream or American buttercream, following the applicable recipe. Once the frosting has come together, tint desired color(s). Set aside. Using a sharp knife, cut the top off each cupcake.
While you CAN just cut it straight across - especially if it has a decent sized dome - I like to cut in towards the center, angling the knife downward, and cutting a complete circle around each cupcake.
Neatly and evenly, use a small knife to cut each top of the cupcakes in half.
Frost cupcakes: spoon or pipe your frosting into the cut crater on top of each cupcake. You can use a coupler and a star tip if you like, I usually just cut the end off my piping bag and do a basic swirl.
Place a pair of “Bat wings” - Cut sides facing each other, a set of tips facing downward- across the center of a frosted cupcake.