Step 1: Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper.
Step 2: On a lightly floured surface, unroll the pizza dough into a rectangle. If it's too springy, let it rest for 5 minutes.
Step 3: In a medium bowl, combine the cooked and crumbled Italian sausage, pepperoni, shredded mozzarella cheese, grated parmesan cheese, and garlic powder. Mix well to ensure everything is evenly distributed.
Step 4: Spread the filling evenly over one half of the pizza dough, leaving a ½-inch border around the edges. Do not overfill.
Step 5: Fold the other half of the dough over the filling. Pinch the edges firmly to seal, then fold the edges under to create a neat seam. You can also crimp the edges with a fork.
Step 6: Carefully transfer the stromboli to the prepared baking sheet. Cut 3-4 diagonal slits on the top of the dough to allow steam to escape during baking.
Step 7: Bake for 20-25 minutes, or until the stromboli is golden brown and cooked through. If desired, you can brush with a little olive oil or an egg wash before baking for a shinier crust.
Step 8: Remove from the oven and let it rest for 5-10 minutes before slicing and serving. This helps the cheese set and prevents the fillings from spilling out.