Mix together:

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

Press and flatten with hands to cover bottom of ungreased 9 x 13 inch pan. Bake about 10 minutes. Sprinkle bottom with 1 cup chocolate chips.

Top with:

2 eggs
1 tsp. vanilla
1 tsp. baking powder
1/2 c. brown sugar
2 tbsp. flour

Spread topping over chips. Bake for about 25 minutes or until topping is golden brown at 350 degrees.