Preheat the oven to 170°C (338°F).
Sift the flour, cocoa powder, and baking powder.
In a bowl, mix together the eggs and sugar.
Add melted butter and milk.
Add the sifted dry ingredients and mix.
Pour the batter into a mold and level the top.
Bake in the 170°C oven for 30 minutes.
Let it cool, then cut into desired sizes.