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

FILLING:

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

FROSTING:

1/4 c. butter
1 square unsweetened chocolate
2 oz. cream cheese (reserved from above)
1/4 c. milk
3 c. powdered sugar
1 tsp. vanilla

In large saucepan, melt butter and chocolate over low heat. Add rest, mix well, and spread in greased and floured 9x13 inch pan.

FILLING: In small bowl, combine 6 oz. cream cheese, sugar, flour, butter, egg, and vanilla until well mixed. Fold in nuts. Spread over dough. Bake 25-30 minutes in 350 degree oven.

Meanwhile, prepare frosting. Remove bars from oven and sprinkle with marshmallows. Return to oven and bake 2 minutes more. Remove from oven and immediately pour frosting over marshmallows. Swirl top to get marbled effect.

FROSTING: In large saucepan, melt butter and chocolate until melted. While still warm, beat in reserved cream cheese and milk. Then beat in rest until smooth.