In bowl, mix whole wheat and all-purpose flours, sugar, apricots, prunes, raisins, bran, baking powder, cinnamon, salt, nutmeg, baking soda and apple, set aside.
Whisk together yogurt, oil and eggs, stir into dry ingredients just until combined. Spread in greased 9inch square cake pan. Bake in 350F 180C oven for 35-40 minutes or until cake tester inserted in center comes out clean.
Let cool in pan on rack, cut into bars. (Bars can be stored airtight container for up to 3 days, or individually wrapped and frozen for up to 1 month.)
