For the cream:
180g. softened butter at room temperature mixed with 1/2 ban. condensed milk. Beat the mixture with a mixer until evenly smooth, then add 1 teaspoon of cocoa powder, if desired, you can add more cocoa powder. Beat the cream well again.
Using a pastry bag with a nozzle, release the cream on the finished cooled cupcakes. Sprinkle the cupcakes with chocolate chips.