1. Preheat the oven to 350°F (180°C).
2. In a bowl, mix the flour and baking powder, then make a well in the center.
3. In another bowl, mix the eggs with the milk and olive oil, then pour this mixture into the well of flour.
4. Mix, then add half of the grated cheese, the mozzarella cut into very small cubes, and the ham cut into cubes.
5. Season with salt, pepper, and oregano or Herbes de Provence.
6. Pour the batter into muffin molds, then sprinkle the remaining grated cheese on top.
7. Bake for about 25 minutes.