While cupcakes are baking, open all the packages of the Twinkies and use a knife to slice in half, making 2 mini sized Twinkies. Once all of your Twinkies are cut in half take your white cookie icing and squeeze out small sized eyes-some may have 2 eyes, while some may have 1 eye (according to the movie). Also, use a small bit of the icing to make a tiny line for the mouth.
Once you have given the "Minions" their eyes and mouths, take some of your Reese's pieces minis and color match their eyes. Brown & Brown, Orange & Orange, ect. Gently press the pieces into the white icing you used to create the eyes. Once that part is finished, use your chocolate sprinkles to make their mouth. Take one sprinkle and place it where you put the white icing to make the mouth. **Don't worry about the eyes or mouths falling off or not sticking, they will stay put !
By now your cupcakes should be cooled enough for icing, so ice them up and take one "Minion" and stick it right on top of the iced cupcake. The will stay put so you don't have to worry about them falling off.