"These hearty and healthy muffins showcase the tangy flavor of wild huckleberries and hearty flavor of whole wheat and oats. Guilt-free and satisfying breakfast your friends and family will love! Even though these are made part with whole wheat flour, they come out surprisingly fluffy."
Preheat oven to 350 degrees F (175 degrees C). Spray 1 muffin tin with cooking spray.
Combine milk, sugar, butter, egg, and vanilla extract in a bowl; mix until completely combined.
Whisk all-purpose flour, 1/2 cup plus 1 tablespoon whole wheat flour, baking powder, and salt in a separate bowl; fold into the milk mixture until batter is just combined. Fold in huckleberries to distribute them evenly.
Pour batter into the greased muffin tin.
Combine the remaining 1/4 cup whole wheat flour, oats, brown sugar, cold butter, and cinnamon in a bowl. Mix until crumbly and sprinkle over the muffins.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 15 minutes.