Marshmallow dessert

Base:
2/3 cup all purpose flour
1/2 tsp. baking powder
1/4 tsp. salt
1/3 cup butter
2 squares unsweetened chocolate
1 cup sugar
2 eggs
1 tsp. vanilla

Topping:
4 cups miniature marshmallows
1 square semi-sweet chocolate
1 tsp. butter

Mix together first three ingredients.
Set aside.
Melt together butter and chocolate.
Beat in remaining ingredients.
Stir in flour mixture.
Spread in greased 8" cake pan
Bake at 350F for 25 minutes.
Immediately sprinkly base with marshmallows.
Broil under pre-heated broiler until golden brown. (about 3 minutes)
Melt together chocolate and butter.
Drizzle over squares.