1. Sift flour with sugar, baking powder and salt. Set aside.
2. Place eggs in large bowl. Use hand mixer or whisk to beat until very thick. Add flour mixture and rest of ingredients; mix well with whisk. (Do not use an electric mixer.) Fold in chocolate chips.
3. Pour into lightly greased 9 x 9 x 5 cm pan. Bake in preheated 325-degree oven for 35 to 40 minutes, or until cake tester inserted in center comes out clean.
4. Place pan on wire rack to cool slightly before cutting into bars.