1. Find a font type and size of the numbers you want to place on the cupcake and print them out on paper.
2. Tear out strips of waxed paper and place the paper with the printed number underneath the waxed paper where you want to pipe.
3. Using stiff royal icing and a small tip such as a PME #1.5, pipe the outline of the number. Make sure there are no gaps in your outline. Slide the printed number underneath the waxed paper and repeat the outlining until you've piped the desired number of outlined numbers.
4. Fill in the outlines with flood consistency royal icing and let dry overnight. If you are using the same color to outline and flood, you do not need to wait for the outline to dry before you flood.
5. Once dry, carefully peel the number from the waxed paper. I used a small, thin offset spatula to help loosen the number from the waxed paper. Make extra, because a few may break.
6. Ice cupcakes and set the number on top. And voila! Cute cupcakes!