Heat oven to 375°F. Coat a 12-cup muffin tin with cooking spray.

Divide pizza dough into 12 portions (about 1 1/4 oz each). Roll into balls. Flatten one piece using your fingers and stretch into a 3-4 round. Repeat with remaining pieces.

Place 1/2 teaspoon of the marinara sauce in the center of each round (no need to spread the sauce), then top each with a piece of mozzarella and 2 slices of pepperoni. Fold the edges of the dough up and round the filling, then pinch them together, forming a small bundle.

Stir the butter, garlic, and salt together in a small bowl. Dip the pizza bombs, one at a time, into the butter mixture, and turn to coat. Place seam-side down into each muffin well. Sprinkle the top of each pizza bomb with 1/4 teaspoon Parmesan cheese and a pinch of Italian seasoning.

Bake until golden-brown, 15 to 20 minutes. Remove from the pan and cool for 5 minutes or until cool enough to handle. Serve with warm marinara sauce.