CRUST:

1 c. flour
1/2 c. butter, soft
1/2 c. brown sugar

Mix up. Pat in greased 9x13 pan. Bake at 350 for 10 minutes.

FILLING:

Mix up in order:

1 c. brown sugar
2 tbsp. flour
1/2 tsp. baking powder
1/4 tsp. salt
12 oz. chocolate chips
2 eggs
1 tsp. vanilla

Pour over baked crust. Spread over top of crust. Bake at 350 for 20 minutes. Remove from oven or they'll be dry.