In bowl, whisk together sugar, yogurt, banana, oil and egg; stir in rolled oats. Let stand for 10 minutes. In large bowl, whisk together unbleached and whole wheat flours, baking powder, cinnamon, baking soda and salt. Pour yogurt mixture over top; sprinkle with blueberries and stir just until dry ingredients are moistened. Spoon into paper-lined muffin or directly into muffin tin cups. Bake in center of 375 degrees F oven until tops are firm to the touch, 20 to 25 minutes. Remove from pan and let cool on rack.