1/2 cup butter or margarine
3 cups graham cracker crumbs
1 1/2 cups mini marshmallows
1 cup semi sweet chocolate chips
10 oz. sweetened condensed milk
Preheat oven to 350 degrees F. Melt butter and add to a 9x13" baking pan along with the graham cracker crumbs. Mix and press down with a fork to form the crust.
Top with marshmallows and chocolate chips. Drizzle the condensed milk over the top. Bake for 25 minutes, until bubbly. Cool for 15 minutes, then chill for 1 hour before cutting into squares.