1/2 c. butter
1 oz. (1 sq.) unsweetened chocolate or 1 env. pre-melted unsweetened baking chocolate
1 c. all-purpose flour
1 c. sugar
3/4 c. chopped nuts
1 tsp. baking powder
1 tsp. vanilla
2 eggs

FILLING:

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

FROSTING:

2 c. miniature marshmallows
1/4 c. butter
1/4 c. milk
1 oz. (1 sq.) unsweetened chocolate or 1 env. pre-melted unsweetened baking chocolate
3 c. powdered sugar
1 tsp. vanilla

Heat oven to 350 degrees. Grease and flour 13 x 9 inch pan. In large saucepan over low heat, melt butter and chocolate. Lightly spoon flour into measuring cup; level off. Add remaining base ingredients; mix well. Spread in prepared pan.

In small bowl, combine all filling ingredients except nuts and chocolate chips. Beat 1 minute at medium speed until smooth and fluffy; stir in nuts. Spread over chocolate mixture; sprinkle evenly with chocolate chips. Bake at 350 degrees for 25 to 30 minutes or until toothpick inserted in center comes out clean. Immediately sprinkle marshmallows over top. Return to oven; bake 2 minutes longer.

In large saucepan, over low heat, melt 1/4 cup butter; 1 ounce chocolate, reserved 2 ounces cream cheese and milk. Remove from heat; stir in remaining frosting ingredients until smooth. Immediately pour frosting over marshmallows and lightly swirl with knife to marble. Chill until firm; cut into bars. Makes 36 bars.