Step 1

Preheat the oven to 350 degrees. Lightly spray a 2-quart casserole dish.

Step 2

Cook the pasta a couple of minutes short of the recommended time on the package. While the pasta is cooking, in a large skillet over medium-high heat, brown the ground beef with the onion, garlic, and bell pepper. Drain the excess fat if necessary.

Step 3

After draining the pasta, stir it into the ground beef mixture. Then, add the pepperoni, jar marinara sauce, and milk and mix well. Pour this mixture into the prepared casserole dish.

Step 4

Top the casserole with the mozzarella cheese and bake it for 30 minutes until the cheese is melted and bubbly.

Step 5

Allow the casserole to cool for about 5 before serving. Sprinkle with some Parmesan cheese for garnish.