This is one of my all-time favorite recipes...from a good friend, Susan Taylor, of the "Black-Eyed Susan" shop here in Yardley.
Melt 1 stick butter and stir in 2 cups brown sugar. Add 2 eggs and 2 tsp. vanilla. Stir in 1 cup and 2 Tbsp. flour, 2 tsp. baking powder, 1 tsp. salt. Pour into a greased 9x13 pan and dot with chocolate chips. Bake at 350 for 30-35 minutes. Cool and cut into squares. Enjoy!