Preheat the oven to 400 degrees. Spray a glass 9x13 baking dish with cooking spray. Set aside.

In a large skillet cook ground beef over medium heat until no longer pink. Drain grease and return ground beef to the skillet and use a meat masher to break meat into small pieces.

Add onions and cook for 5 minutes, stirring often so they do not burn. Add minced garlic and cook for an additional 2 minutes, stirring often.

Add Italian seasoning, salt, black pepper, and pepperoni. Stir well and continue to cook for an additional 3-5 minutes, or until pepperoni is cooked and heated through.

Add spaghetti sauce to the meat mixture and stir well. Let simmer for 3 minutes.

Add the meat mixture to the bottom of the baking dish and spread out evenly using a rubber spatula. Top with shredded mozzarella cheese.

Place in the oven at 400 degrees while you combine the bubble up top mixture. You want your baking dish to be very hot when you pour the bubble up mixture into it.

In a separate medium mixing bowl combine sifted flour, eggs, milk, vegetable oil, and salt. Use a large spoon to mix together. Don’t over mix. (NOTE: This batter will be a bit runny and should be able to pour onto the top of the casserole)

Remove the baking dish from the oven and pour the bubble up top over the meat mixture, making sure to get the top all the way to the edges of the casserole dish. Sprinkle ⅓ cup shredded parmesan cheese over the top of the bubble up top and place in the oven.

Cook at 400 degrees for 30 minutes, or until the bubble up top has puffed up and is a deep golden brown color.

Remove from the oven and serve immediately.