Preheat your oven to 375°F (190°C).
Unroll the crescent roll dough and separate it into triangles.
Press the triangles into the greased muffin tin, forming a small cup for the fillings.
Spread about a teaspoon of pizza sauce into each dough cup.
Layer shredded mozzarella cheese over the sauce.
Add pepperoni and chopped green bell pepper on top of the cheese.
Sprinkle dried oregano and garlic powder over each mini pizza.
Bake in the preheated oven for 12-15 minutes, or until golden brown.
Allow to cool for a few minutes before removing from the muffin tin.
Serve warm with extra pizza sauce on the side, if desired.