Preheat your oven to 375° degrees F. Grease a 9x13 inch baking dish or casserole dish.
In a large pot of boiling salted water, cook the tortellini according to package instructions until al dente. Drain and set aside. Do not rinse.
In a large mixing bowl, combine the cooked tortellini, pizza sauce, sliced pepperoni, and a cup of the mozzarella cheese, and ½ cup of the Parmesan. Stir until everything is evenly coated.
Pour the tortellini mixture into the prepared baking dish, spreading it evenly. Top with the remaining mozzarella cheese and Parmesan cheese.
Cover with foil and bake in the preheated oven for about 30 minutes. Remove foil and bake an additional 10 minutes or until the cheese is bubbly and golden brown.
Remove from the oven and let it cool for a few minutes. Garnish with fresh basil or parsley if desired. Serve warm.
