2 c. unsifted flour
2 tsp. baking powder
1 tsp. salt
3/4 c. butter, softened
3/4 c. sugar
3/4 c. dark brown sugar
1 tsp. vanilla
3 eggs
1 (12 oz.) pkg. chocolate chips

(I have used light brown sugar and it makes no difference).

Preheat oven to 350 degrees. In small bowl, combine flour, baking powder and salt; set aside. In large bowl, combine butter, sugar, brown sugar, and vanilla; beat until creamy. Add eggs, one at a time, beating well after each addition. Gradually add flour mixture, mix well. Stir in chocolate chips. Spread evenly into well greased 13 x 9 inch pan or 15 x 10 inch pan. Bake at 350 degrees for 30 to 35 minutes. Cool, cut into squares.