1. Preheat oven to 350F (180C). Lightly butter a 9x5-inch (1.5-L) loaf pan or coat with cooking spray. In a large bowl, using a fork, stir flours with baking powder, baking soda, cinnamon, salt and ginger until blended. Stir in ground flaxseed or if using whole flaxseeds, toast in a dry skillet over medium-high heat, shaking often, from 3 to 4 minutes. Crush, then stir into flour mixture with nuts. Make a well in the centre.
2. In a mixing bowl, lightly beat eggs, then stir in mashed bananas, syrup, oil and vanilla until blended. Pour into well in flour mixture. Stir just until evenly mixed. Immediately pour batter into prepared pan and smooth the top. Bake in centre of 350F (180C) oven until a cake tester inserted in the centre right to the bottom comes out clean, about 50 minutes. Let stand 5 minutes in pan on a rack. Then turn out on rack to cool. Loaf will keep at room temperature for up to 3 days or can be frozen.