Note: You can use regular whole wheat flour or white wheat flour, which gives a lighter texture. Both can be found in the baking aisle with other flours.
1. Preheat oven to 375 degrees F. Coat the cups of a 12-cup muffin tin with cooking spray.
2. Prepare crumb topping. In a medium bowl, whisk together oats, flour, and brown sugar. Drizzle melted butter and water over mixture and stir until moistened. Set aside.
3. Prepare muffins. Set aside 1 Tbsp. of the all-purpose flour. In a large mixing bowl, whisk together remaining flour, whole wheat flour, oats, sugar, baking powder, baking soda and salt.
4. In a separate bowl, whisk together egg, vanilla, buttermilk, oil, and applesauce.
5. Add wet ingredients to dry ingredients and stir until just combined (lumps are OK; don't overmix). Toss blueberries with reserved flour and gently stir them into muffin batter (too much stirring will result in purple muffins).
6. Divide batter evenly among muffin cups. Sprinkle each muffin with 1 Tbsp. of the crumb topping. Bake at 350 degrees F for 22 to 26 minutes, until golden and a toothpick inserted in the center of a muffin comes out clean. Let cool in pan for 10 minutes before transferring to a cooling rack.
Source: Hannaford fresh Magazine, July - August 2008