1/2 c. butter
1/2 c. packed brown sugar
1 c. flour
1/2 c. graham crackers, crushed
2 c. miniature marshmallows
1 (6 oz.) pkg. semi-sweet chocolate chips
1/2 c. chopped walnuts or pecans

Cream butter and sugar until light and fluffy. Add combined dry ingredients; mix well. Press onto bottom of greased 9 inch square baking pan. Sprinkle with remaining ingredients. Bake at 375 degrees for 15 to 20 minutes or until golden brown. Cool, cut into bars.