http://crockpot365.blogspot.com/2010/05/slow-cooker-puffy-pizza-casserole.html
1 pound lean ground beef
1 small onion, diced
1 garlic clove, minced
1 (1.5) ounce packet of spaghetti mix (like McCormick or you can make your own using the recipe below)
1/2 teaspoon oregano
1 (15-ounce) can tomato sauce
1/2 cup water
For puffy topping:
1 cup all-purpose flour
1 cup milk
2 eggs
1 cup shredded mozzarella cheese
20 pepperoni slices
1/2 cup sliced olives, optional
Homemade Spaghetti Sauce Mix
yields 1 packet
1 1/2 teaspoons kosher salt
1 tablespoon cornstarch
1 tablespoon dried minced onion
1 tablespoon parsley flakes
1 teaspoon granulated white sugar
1/4 teaspoon garlic powder
2 teaspoons green pepper flakes
3/4 teaspoon Italian seasoning
The Directions.
Use a 4 quart slow cooker (if you only have a 6, that's okay, it will just cook faster. Check it after 3 hours on high.)
In a very large skillet, brown beef, onion, and garlic on the stove top. Drain fat, and add spaghetti sauce mix, oregano, tomato sauce, and water. Stir over low heat until tiny bubbles appear. Remove from heat and scoop into the slow cooker (you might want to spray it with cooking spray).
In a mixing bowl, combine the ingredients for your puffy topping: flour, milk, eggs, and cheese. Pour evenly over the top. Place pepperoni slices and olives on top of the topping.
Cover and cook on high for 4 hours, or until the topping has turned golden brown, puffed up, and pulled away from the sides.