Beat all of the cupcake ingredients together in a large bowl. Pour the batter into the lined wells of your cupcake pan. Bake the cupcakes at a reduced heat from the original preheated oven. Once a toothpick inserted into the center of a cupcake comes out clean they can be transferred to a wire rack to cool completely.
Pipe frosting onto each cooled cupcake. Spread a little peanut butter onto each peanut butter cup. Dip the peanut butter tops into sprinkles. Press the peanut butter cups into the frosting on top of the cupcakes. Stick each end of the airhead into the frosting to form a rainbow.