Recipe borrowed from La Receta de la Felicidad
7 ounces semi-sweet chocolate, chopped
1 stick butter (1/2 cup), cut into 8 pieces
1 cup sugar
1 teaspoon vanilla
Pinch of salt
1 cup flour
3 tablespoons unsweetened cocoa powder
12-16 empty egg shells, reserve yolks/whites for another recipe (include the 3 eggs in the recipe)
Powdered sugar, optional, for dusting
Prepare egg shells by carefully poking a small hole in bottom of each egg using a corkscrew, nail or large needle. Open the hole up so the tip of a piping bag can be inserted. Insert a wooden skewer to break up the yolk, then shake out the contents into a bowl (collect 3 separately to use in the recipe).
When egg shells are all emptied, rinse them well and place them in a large container of salt water (hold them under to fill them with water so they sink). Soak about 30 minutes, then rinse and turn upside down on paper toweling to drain.
Using a funnel, put about 1 teaspoon of vegetable oil in each shell. Gently shake to distribute and turn upside down to drain any excess. Set aside to make batter.
Preheat oven to 350º.
Melt chocolate and butter gently in microwave, using 30 second increments, stopping and stirring till melted and smooth. Allow to cool to warm.
In a medium bowl, whisk the eggs and sugar. Whisk in eggs, one at a time. Mix in vanilla. Add warm chocolate and mix well. Stir in flour, salt, and cocoa powder till just combined.
Place eggs, hole side up, in mini muffin tin, using aluminum foil nests to keep upright. Put batter into a piping bag fit with a round tip. Fill the eggs about 3/4 full with batter. Gently clean any batter off of shells with a damp cloth. Bake about 15-20 minutes. Remove any overflow when brownies are still warm and wipe with damp cloth.
Cool, remove top of shell or all of shell to serve.
If you only want to make 3-4 eggs like I did, put remaining batter into a non-stick foil lined or well greased 8 x 8 pan. Bake 20-25 minutes. Cool on rack. Serve with a dusting of powdered sugar if desired.