- 1/3 cup whole flaxseeds (see Ingredient note)
 - 1 cup whole wheat flour
 - 14 tablespoons all-purpose flour
 - 1 1/2 teaspoons baking powder
 - 1/2 teaspoon baking soda
 - 1/4 teaspoon salt
 - 1 teaspoon ground cinnamon
 - 2 large eggs
 - 1/2 cup pure maple syrup
 - 1 cup buttermilk (see Tip)
 - 1/4 cup canola oil
 - 2 teaspoons freshly grated orange zest
 - 1 tablespoon orange juice
 - 1 teaspoon vanilla extract
 - 1 1/2 cups fresh blueberries
 - 1 tablespoon granulated sugar
 
- Preheat oven to 400 degrees F. Coat 12 muffin cups with cooking spray.
 - Grind flaxseeds in a spice mill (such as a clean coffee grinder) or dry blender. Transfer to a large bowl. Add whole-wheat flour, all-purpose flour, baking powder, baking soda, salt and cinnamon; whisk to blend.
 - Whisk eggs and maple syrup in a medium bowl until smooth. Add buttermilk, oil, orange zest, orange juice and vanilla; whisk until blended. Add to the flour mixture and mix with a rubber spatula just until dry ingredients are moistened. Fold in blueberries. Scoop the batter into the prepared muffin cups. Sprinkle tops with granulated sugar.
 - Bake the muffins until the tops are golden brown and spring back when touched lightly, 15 to 25 minutes. Let cool in the pan for 5 minutes. Loosen edges and turn muffins out onto a wire rack to cool slightly.