Preheat oven to 375°F. Grease a 9x13-inch baking dish.
Cook macaroni in salted water until just shy of al dente. Drain and set aside.
In a large skillet over medium-high heat, cook ground beef, Italian sausage, onion, and bell pepper until the meat is browned and the vegetables are softened.
Drain excess grease.
Add garlic and cook for 30 seconds, stirring constantly.
Stir in 23 1/2 ounces of the pizza sauce, 1 teaspoon Italian seasoning, garlic powder, and red pepper flakes. Simmer for 3 to 5 minutes.
In a large mixing bowl, combine: - cooked macaroni - meat sauce mixture - 2 cups mozzarella cheese - provolone cheese - about 2 ounces of pepperoni Spread half of the mixture into the prepared baking dish.
Sprinkle about 1 1/2 ounces pepperoni evenly over the center layer.
Top with the remaining pasta mixture and spread evenly.
Spoon the reserved 1/2 cup pizza sauce over the top.
Sprinkle with the remaining 2 cups mozzarella cheese.
Arrange the remaining pepperoni slices over the cheese.
Sprinkle with Parmesan cheese and the remaining 1/2 teaspoon Italian seasoning.
Bake uncovered for 20 to 25 minutes, or until hot and bubbly.
Broil for 1 to 2 minutes, if desired, for additional browning.
Let rest for 10 minutes before serving.
Garnish with torn fresh basil leaves just before serving, if desired.