01 - Preheat oven to 350°F. In a bowl, combine all-purpose flour, baking powder, salt, and dried oregano. In a separate bowl, whisk together the egg, milk, and olive oil. Pour wet ingredients into dry ingredients and stir until just combined.
02 - Gently fold shredded mozzarella, diced tomatoes, and chopped black olives into the batter until evenly distributed.
03 - Grease a mini muffin tin or line with paper liners. Fill each cup about three-quarters full with batter. Sprinkle with grated parmesan. Bake for 12 to 15 minutes, or until muffins are golden and set.
04 - Allow muffins to cool slightly in the tin. Garnish each with fresh basil leaves and serve warm.