Bake and cool cupcakes. Cover with plastic wrap until ready to fill to keep cupcakes fresh. Fill a pastry bag fitted with a bismarck tip (tip #230) with cupcake filling. *A bismarck tip is a specially designed tip for filling pastries. Poke the bismarck tip into the top of each mini cupcake and squeeze to fill. The mini cupcake will begin to expand, and you will know it has been filled.
Instructions and image taken with permission fromVi Whittington and Autumn Carpenter's Book, Creative Cupcakes.