Preheat your oven to 400°F (200°C) and prepare a baking sheet with parchment paper.

Roll out the pizza dough into a rectangular shape, about 12x10 inches in size, on a lightly floured surface.

Spread marinara sauce evenly over the rolled-out dough, leaving about an inch around the edges. Sprinkle shredded mozzarella cheese on top.

Add sliced pepperoni, cooked Italian sausage, bell peppers, and onions evenly over the cheese.

Sprinkle Italian seasoning over the top for extra flavor.

Carefully roll the dough away from you, taut enough to keep all fillings inside.

Pinch together the edges of the dough to seal the Stromboli.

Beat the egg in a small dish and brush it over the top of the rolled Stromboli.

Cut a few slits in the top of your Stromboli with a sharp knife to allow steam to escape.

Place your Stromboli on the prepared baking sheet and bake for about 25 minutes or until the crust is golden brown.

Allow it to cool for a few minutes before slicing. Serve with extra marinara sauce for dipping.