Preheat oven to 350 degrees. Flour and butter a 9x13 pan. Sift flour into a bowl. Mix flour, baking powder, salt and baking soda. Set aside. Melt butter. In mixing bowl, place melted butter and add sugar, mixing well. Add eggs,vanilla, mixing well. Add flour slowly, blending. Batter will be slightly thick.
Spread in pan. Sprinkle chocolate chips and pecans over all. Bake for 25-30 minutes.