Sugar cookie:

1. Beat the butter and sugar on a medium speed until light and fluffy (2-3 minutes).
2. Add the egg and vanilla and mix until just combined.
3. Scrape down the sides of the bowl, add the flour, and mix on low until just combined.
4. Increase the speed to medium and continue beating until the dough is clumps and easily pulls away from the sides of the bowl. The dough will be soft but shouldn't be sticky.
5. Flatten the dough into a disc, wrap in plastic wrap and refrigerate for at least 1 hour.
6. Roll the dough out on a lightly floured surface to 1/4" thick.
7. Cut out the dough with a 2 1/2" round cookie cutter. Use the wide end of a piping tip to cut a circle out of half of the cookies about 1/2" from the edge.
8. Place on a parchment paper lined baking sheet at least one inch a part.
9. Bake at 350F for 7-9 minutes, or until no longer shiny on top.
10. Remove from the oven and allow to cool on the baking sheet.

Cookie assembly:

1. Pipe or spread an 1/8" layer of frosting onto the cookies without the holes, working it almost all the way out to the edges.
2. Place the cookies with the hole on top, gently pressing down to seal.
3. Spoon the remaining frosting into a piping bag and clip a small opening at the end.
4. Pipe a dollop in the bottom of the hole to create the bunny's cheeks/mouth and two strips from the top of the cookie down to the hole for the ears.
5. Spoon the black frosting into a piping bag, clip a very small opening and pipe two eyes. Use two small dots of white frosting to create a reflection if you'd like.
6. Put the pink frosting into a piping bag, clips a small opening in the end, and pipe a heart shape to create the nose.
7. You can also pipe two dollops on the out rim of the cookie under the hole to create feet.