I started by shaping the stems and caps of the toadstools out of colored fondant.
Once those had set up a little bit, I put them together with a little bit of royal icing and added the spots.
Aren't they great? It looked a little like some Mario video game had descended upon my kitchen with all the toadstools sitting on the table!
Once the cupcakes were done, I piped a swirl of green icing in top and put a couple of toadstools in each one.
And here's the whole set...