Preheat oven to 375˚F/190°C. Grease a 24-cup mini-muffin pan.
In a large bowl, whisk together flour, baking powder, salt and oregano; whisk in milk and egg. Stir in mozzarella and pepperoni; let stand 10 minutes.
Stir batter, and divide among mini-muffin cups. Bake until puffed and golden, 20-25 minutes.
Warm pizza sauce, then stir in 1 tablespoon basil. Sprinkle puffs with remaining 1 tablespoon basil. Serve puffs with pizza sauce for dipping. (if desired). Leftovers can be stored in the refrigerator for up to a week or freeze and use as needed.