BAR:

1/2 c. butter
1 sq. unsweetened chocolate
1 c. sugar
1 c. flour
1/2 c. nuts, chopped
1 tsp. baking powder
1 1/2 tsp. vanilla
2 eggs

FILLING:

1 (8 oz.) pkg. cream cheese, softened (reserve 2 oz. for frosting)
1/2 c. sugar
2 tbsp. flour
1/2 c. butter, softened
1 egg
1 tsp. vanilla
1/4 c. nuts, chopped
1 (6 oz.) pkg. semi-sweet chocolate chips

FROSTING:

2 c. miniature marshmallows
1/4 c. butter
1 sq. unsweetened chocolate
Remaining 2 oz. cream cheese
1/4 c. milk
1 lb. (3 c.) confectioners sugar
1 1/2 tsp. vanilla

In large saucepan over low heat, melt 1/2 cup butter and 1 ounce chocolate. Add remaining bar ingredients; mix well. Spread in greased and floured 13 x 9 inch pan. In small bowl, combine 6 ounce cream cheese with next 5 filling ingredients. Blend until smooth and fluffy. Stir in nuts. Spread over chocolate mixture. Sprinkle with chocolate chips. Bake at 350 degrees for 25 to 35 minutes until toothpick inserted in center comes out clean. Sprinkle with marshmallows and bake 2 minutes longer. In large saucepan over low heat, melt 1/4 cup butter, 1 ounce chocolate, remaining 2 ounces cream cheese and milk. Stir in powdered sugar and vanilla until smooth. Immediately pour over marshmallows and swirl together. Cool before cutting.