Once cooled, core out the center of your cupcakes (if you want to fill them with buttercream). I used some type of apple corer to do this (I’m not sure exactly what it’s intended use is, I just found it in my drawer).
Using a piping bag (or ziploc bag with a tip), fill the center with some frosting then replace the top. Frost with the buttercream. It doesn’t have to be particularly pretty, you’re going to cover it up with sprinkles anyway.
Fill a bowl with the sanding sugar, flip the cupcake over and gently smush into the sprinkles to fully coat.
Cut some vanilla wafers in half for the ears (gently! this part is tricky. they were shooting all over when I was cutting them) and stick on each side of the cupcake.
Add a whole vanilla wafer for the mouth and use gel icing (or melted chocolate) to draw on the mouth & nose. I gave mine different faces & personalities.
I bought pre-made eyeballs, but I didn’t like them, so I flipped them over and drew on my own pupils with the icing.