Mix flour, cocoa powder, sugar, and yeast.
Add milk and eggs, then knead the dough.
Add butter and knead again.
Let the dough rise for 1 hour.
Divide the dough and shape it into balls.
Preheat the oven to 180°C.
Place chocolate chips on top of the dough.
Bake in the oven at 180°C for 15 minutes.