Lightly grease a 13-inch pizza pan. For crust, in a large mixing bowl beat margarine or butter with an electric mixer on medium to high speed for 30 minutes. Add about half of the flour, the granulated sugar, brown sugar, egg, and vanilla. Beat mixture until thoroughly combined. Beat in remaining flour.
Spread dough evenly into prepared pizza pan. Bake in a 350 degree F oven for 25 to 27 minutes or until edges are golden brown and center is set. Remove from oven. Sprinkle evenly with marshmallows, chocolate pieces, and peanuts. Drizzle with caramel ice cream topping.
Bake about 5 minutes more or until marshmallows are golden. Cool on a wire rack. Makes 12 servings.