Begin by filling a large pot with water and adding a pinch of salt. Bring it to a rolling boil, then add the egg noodles. Cook them until they are al dente, approximately 7 to 9 minutes. Once cooked, drain the noodles and set them aside.

Preheat your oven to 350 degrees F (175 degrees C) to prepare for baking.

In a medium skillet, heat over medium-high heat. Add the ground beef, chopped onion, bell pepper, and minced garlic. Cook and stir for about 5 to 7 minutes, or until the beef is browned and crumbly. Be sure to drain any excess fat from the skillet.

Combine the cooked egg noodles with the browned beef mixture. Stir in the pizza sauce, pepperoni slices, and milk until everything is thoroughly mixed.

Transfer the mixture into a 2-quart casserole dish, spreading it evenly.

Place the casserole in the preheated oven and bake for 20 minutes.

After 20 minutes, remove the dish from the oven and sprinkle the shredded mozzarella cheese on top. Return it to the oven and bake for an additional 5 to 10 minutes, or until the cheese is melted and bubbly.

Allow the casserole to cool slightly before serving to enhance the flavors and make it easier to serve. Enjoy your delicious and comforting pizza casserole!