BASE:

1/2 c. butter
1 oz. unsweetened chocolate
1 c. flour
1 c. sugar
1 tsp. baking powder
1 tsp. vanilla
2 eggs
3/4 c. chopped nuts

Melt butter and chocolate. Beat eggs, add sugar and mix. Add remaining ingredients including chocolate mixture. Spread in greased and floured 9 x 13 pan.

FILLING:

8 oz. cream cheese softened, reserve 2 oz. for frosting
1/2 c. sugar
2 tbsp. flour
1/2 tsp. vanilla
1 egg
1/4 c. chopped nuts

Combine all filling ingredients except nuts. Beat 1 minute until fluffy; stir in nuts. Spread filling over base. Sprinkle with 1 cup chocolate chips. Bake at 350 degrees for 25 to 35 minutes or until toothpick inserted in center comes out clean. Immediately sprinkle 2 cups miniature marshmallows over top and bake 2 minutes more.

FROSTING:

1/4 c. butter
1/4 c. milk
1 oz. unsweetened chocolate
Reserved 2 oz. cream cheese
3 c. powdered sugar
1 tsp. vanilla

Combine over low heat stirring until melted and well blended. Stir in powdered sugar and vanilla until smooth. Spread over marshmallows and lightly swirl with knife to marble. Refrigerate until firm and cut into bars.