1 pkg. (18 oz.) chocolate fudge cake mix
1/2 c. brown sugar
1/3 c. peanut butter
1/4 c. butter
1/3 c. milk
1 egg

Combine first 4 ingredients and mix well. Add milk and egg. Pour into greased 9x13 pan. Bake at 350 degrees for 25 minutes or until done. Remove from oven and sprinkle on 3 cups miniature marshmallows. Bake 3 minutes longer (or until melted).

FROSTING:

1/2 c. powdered sugar
1/4 c. milk
2 tbsp. butter
1 tsp. vanilla
1/2 c. chocolate chips

Combine first 4 ingredients and bring to a boil. Add chocolate chips and stir until melted. Drizzle over marshmallows. Cool well.