To make a cupcake out of a onesie, first smooth out the onesie flat, tucking any tags away, then neatly fold in the arms toward the middle two times on each side to create a tight, long rectangle. Place a sock at one end of the rectangle, overlapping the toes of the folded onesie. Roll the sock and onesie into a tight ball, having left the sock tip visible at the top. Flip the ribbed ankle part of the sock over to hold the rolled onesie in place.