allow your cupcakes to completely cool

add green frosting to your bag that already has a star or grass tip in place

frost the cupcakes by squeezing out the frosting going in an up and down pattern - squeeze onto the cake - pull bag straight up, squeeze down, pull straight up, etc...

spread some chocolate frosting on the top of a mini Reese's

place the candy on the cupcake and shake gold sprinkles onto the chocolate frosting - some will spill over  and that's great

add the rainbow at an angle so it looks like it is pointing toward the sky