Combine hamburger and spaghetti sauce and spread in greased 9x13" baking pan. Top with cheese. (We also decided to add a layer of pepperoni as well.) Combine remaining ingredients in a blender and process until smooth. Then pour over pizza ingredients. Bake, uncovered, at 400° for 25-30 minutes or until golden brown. 12 servings.
Well, I don't know about the 12 servings, but it did serve more than 3 people, and the leftovers were just as delicious the next day.