1
Mix the flour, salt, pepper, baking powder, and oregano in a big bowl. Add the prosciutto and mozzarella, and mix with your hands, so the prosciutto and mozzarella don't stick together in big clumps.
2
Whisk the melted (but cooled) butter with the eggs and add the mixture to the big bowl.
3
Combine everything with your hand until a dough forms, adding a few more tablespoons of butter as needed (I add 4).
4
Form a dough ball, transfer it to the baking sheet, and flatten it into a round shape to a diameter of about 21 cm / 8 inches.
5
Cut the dough into 8 triangles, separate them, and, optionally, grate your favorite hard cheese on top.
6
Bake for 20 minutes at 350 F. Take out and serve immediately. The best way to store them is to freeze them and reheat them in the oven before serving.