Preheat oven to 350°F. Lightly grease a 9 x 5-inch loaf pan.

Mix whole wheat pastry flour, all-purpose flour, flaxseeds, baking powder, baking soda and salt in a medium bowl. Remove 2 tablespoons flour mixture and toss with raspberries and cranberries in a separate bowl. Stir together bananas, brown sugar, butter, eggs and vanilla in a separate large bowl. Add flour mixture to banana mixture, stirring just until combined. Gently fold in raspberries and cranberries until evenly blended. Pour batter into prepared loaf pan.

Bake about 1 hour, or until browned and a pick inserted in center comes out clean. Cool in pan 20 minutes. Remove from pan and cool completely on a wire rack before slicing.