Popover Upside Down Pizza

From the Recipe Shoebox.

The ingredients:
1 lb. ground beef (or ground turkey)
1 large onion, chopped
2 cups spaghetti sauce (can substitute with 1 can (15-ounce) tomato sauce plus one envelope spaghetti sauce mix)
1 cup chopped pepperoni
1 pkg. (8-ounces) sliced mozzarella cheese ( I used 2 cups of shredded mozzarella instead)
2 eggs
1 cup milk
1 Tbs. oil
1 cup flour
1/2 tsp. salt
1/2 cup grated Parmesan cheese

Directions:  In a large skillet, brown ground beef or turkey with onion.  Pour off excess fat.  Add spaghetti sauce (or tomato sauce and spaghetti sauce mix) and pepperoni and simmer 10 minutes.  Spoon into greased 9x13-inch baking pan. Top with cheese.  Place in 400 degree oven to keep hot.  To prepare popover batter, beat together eggs, milk, and oil.  Add flour and salt; beat until smooth.  Pour over hot pizza filling, being careful to cover filling completely.  Sprinkle with Parmesan cheese.  Bake at 400 degrees for 30 minutes, until puffed and deep golden brown.  Cut into squares and serve immediately.  Makes 6 servings.  Enjoy!