Preheat oven to 375 degrees Fahrenheit (190 degrees Celsius) and lightly grease a 9x13 inch baking dish.

In a large skillet over medium-high heat, cook the Italian sausage until browned and crumbled; drain excess fat.

Cook the tortellini in boiling salted water for 2 minutes less than the package directions; drain.

In a large mixing bowl, combine the par-cooked tortellini, marinara sauce, browned sausage, half of the pepperoni slices, bacon, garlic powder, and Italian seasoning.

Transfer the mixture to the prepared baking dish and spread into an even layer.

Top with the shredded mozzarella cheese, remaining pepperoni slices, and grated Parmesan.

Bake for 20 to 25 minutes until the cheese is melted and bubbling.

Remove from oven and let stand for 5 minutes before serving.