Preheat the oven to 375°F. Grease a muffin pan with cooking spray.
Divide the pizza dough into 12 equal portions, rolling each into a ball then flattening them slightly.
Add 1/2 teaspoon marinara sauce to the center of each piece of dough (reserve the remaining marinara sauce for dipping). Divide the mozzarella cheese among the pizza pockets then add three mini pepperoni to each pizza pocket.
Gather up the edges of each pizza pocket and pinch it together tightly to form a ball.
Place one pizza pocket inside each muffin tin cup.
In a small bowl, stir together the melted butter and garlic powder. Brush the tops of the pizza pockets with the garlic butter then top them with a pinch of Italian seasoning.
Bake the pizza pockets for 18 to 22 minutes until golden brown and the dough is cooked through.
Serve warm with marinara sauce for dipping.