In a small bowl mix together the oil, sugar, maple syrup, egg, milk, vanilla, and mashed bananas.
In a large bowl, stir together the whole wheat pastry flour, all-purpose flour, ground flax seed, baking powder, salt, and cinnamon.
Make a small well in the center of the dry ingredients and pour in all the wet ingredients from the first bowl. Stir until dry ingredients are moistened, but do not over stir.
Spray a 9" x 5" loaf pan with non-stick pan spray and sprinkle with a little flour. Pour banana bread batter into pan and set aside.
Pre-heat oven to 350° F. After oven is heated, place ban of banana bread batter into oven on the middle rack. Bake for 55 to 60 minutes. Bread is done when a toothpick inserted into the middle of the bread comes out clean.
Remove from oven and let cool in the pan for 5 minutes. Remove from pan and finish cooling on a wire rack before slicing into 1/2" slices.