Cook the Pasta:

• Preheat your oven to 350°F (175°C).​

• Cook the pasta in a large pot of salted boiling water until al dente, following package instructions. Drain and set aside.​

Prepare the Meat Sauce:

• In a large skillet over medium heat, cook the ground beef or sausage until browned.​

• Add the diced onion and cook until softened, about 3-4 minutes.​

• Stir in the minced garlic and cook for an additional minute.​

• Drain any excess fat from the skillet.​

• Pour in the marinara or pizza sauce and add the Italian seasoning, salt, and pepper. Stir to combine and let the sauce simmer for 5 minutes.​

Assemble the Casserole:

• In a large mixing bowl, combine the cooked pasta with the meat sauce, ensuring the pasta is well coated.​

• Transfer half of the pasta mixture into a greased 9×13-inch baking dish.​

• Sprinkle 1 cup of shredded mozzarella cheese over the pasta layer.​

• Add half of the sliced pepperoni on top of the cheese.​

• Repeat the layers with the remaining pasta mixture, another cup of mozzarella cheese, and the remaining pepperoni slices.​

• Sprinkle the grated Parmesan cheese over the top.​

Bake:

• Cover the baking dish with aluminum foil and bake in the preheated oven for 20 minutes.​

• Remove the foil and bake for an additional 10-15 minutes, or until the cheese is melted and bubbly.​

Serve:

• Remove from the oven and let the casserole cool for a few minutes before serving.​

• Garnish with optional toppings like sliced black olives, diced bell peppers, or sliced mushrooms if desired.​

• Serve warm and enjoy!​