Preheat oven to 425 degrees.

Spray a muffin tin with non stick cooking spray and line muffin tin with muffin liners.

In a small bowl, combine 1 tablespoon of melted butter, oats, brown sugar, 1 tablespoon of white whole wheat flour and cinnamon and set aside.

In a large mixing bowl, whisk together 2 cups of white whole wheat flour, baking powder, salt, baking soda.

In another small bowl, combine reduced fat sour cream, sugar, vegetable oil, 2 tablespoons of melted butter, vanilla and eggs.

Pour sour cream mixture into dry ingredients and stir just until combined.

Gently fold in fresh blueberries.

Divide muffin batter into muffin liners.

Sprinkle with streusel topping.

Bake at 425 for first 5 minutes, then reduce oven temperature to 375 and bake an additional 13 minutes.