Preheat oven to 350°F.
Add olive oil to a large skillet over medium-high heat. Sauté ground Italian sausage, peppers, and onions, until sausage is no longer pink and vegetables are tender. Remove from heat, drain excess grease, and set aside.
Arrange the bottom halves of the Sandwich Potato Rolls in a greased 13×9 baking dish and bake in preheated oven for 4-5 minutes, until lightly toasted.
Remove rolls from oven and sprinkle with one cup of shredded mozzarella cheese. Top with the sausage and pepper mixture.
Spread marinara sauce on top then sprinkle with remaining cheese. Place top halves of Sandwich Potato Rolls on top.
In a small bowl, mix together melted butter, Italian seasoning, and garlic powder. Spread mixture over tops of sandwiches, reserving a small amount for later.
Bake, uncovered, for 20-25 minutes or until golden-brown and heated through.
Top sandwiches with remaining butter mixture and serve immediately.