Tyler's Homecoming Luncheon Bars

Otherwise known as Rocky Road Brownies, mom served these yummy treats at Tyler's missionary homecoming luncheon.

1/2 c. butter or margarine
1/4 c. buttermilk
1 c. semi-sweet chocolate chips
1/2 c. unsweetened cocoa
1 tsp. vanilla
1 c. sugar
1 c. miniature marshmallows
1 egg
1/2 c. flour
1 c. chopped walnuts

Preheat oven to 350 degrees. Lightly grease 8x8x2 square pan. Combine butter and cocoa in medium sized heavy saucepan over low heat, stirring constantly until smooth. Remove from heat; stir in sugar, egg, flour, buttermilk and vanilla. Mix until smooth. Spread batter evenly in prepared pan. Bake 25 min. or until center feels dry. Remove from oven; sprinkle marshmallows, walnuts and chocolate chips over top. Return to oven for 3-5 minutes or just until topping is warmed enough to hold together. Cool in pan on wire rack.