Shortbread Brownies

1 C flour
1/4 C packed brown sugar
1/2 C butter
3/4 C miniature semisweet chocolate chips
1 1/3 C sugar
3/4 C flour
1/2 C unsweetened cocoa powder
1 1/2 t baking powder
1/2 t salt
3 eggs
1/3 C butter, melted
1 T vanilla

Preheat oven to 350. Line a 9x9x2 inch baking pan with foil; set aside. In mixing bowl stir together the 1 C flour and the brown sugar. Cut in the 1/2 C butter until mixture resembles coarse crumbs. Stir in 1/4 C of the chocolate pieces. Press into prepared pan. Bake for 8 minutes. Meanwhile, in a large mixing bowl stir together sugar, 3/4 C flour, cocoa powder, baking powder, and salt. Add eggs, the melted butter, and vanilla; beat by hand until smooth. Stir in the remaining 1/2 C chocolate pieces. Carefully spread over crust in pan. Bake for 40 minutes. Cool in pan on a wire rack. Remove brownies from pan and remove foil. Cut into bars.