La Receta de la Felicidad, a Spanish-language site, has Sandeea Cocina’s great little HOWTO for baking brownies inside blown eggshells. You make a hole in the shell with a corkscrew, stand the shell up in a muffin tin with tin-foil supports, and fill the egg with brownie batter using a piping bag and bake (make sure to leave room in the egg to allow for cakeular expansion!). My mom used to make me Jello-filled hollow eggs, but this is a whole ‘nother level of egg-hacking.
Brownie: por fin llegó el día del brownie! (La Receta de la Felicidad)
Brownie: Finally the day came brownie! (Google Translate)
(via Neatorama)