Whole Wheat Lemon Blueberry Muffins

I found the following recipe for blueberry muffins on http://www.allrecipes.com/:

2 cups all-purpose flour
2 teaspoons baking powder
1/2 teaspoon salt
1 1/2 tablespoons all-purpose flour
1 1/2 cups fresh blueberries
1/2 cup butter
3/4 cup white sugar
2 eggs
1 teaspoon vanilla extract
1/4 teaspoon lemon zest
1/2 cup milk
2 tablespoons all-purpose flour
5 tablespoons white sugar
1/2 teaspoon ground cinnamon
2 tablespoons butter, diced
Directions
Preheat oven to 375 degrees F (190 degrees C). Grease 12 muffin cups or line with paper muffin liners.
Combine 2 cups flour, 2 teaspoons baking powder, and 1/2 teaspoon salt in medium bowl. In a small bowl, sprinkle 1 to 2 tablespoons flour over blueberries, and set aside. (This simple trick will keep you from having "purple" batter)
In a large bowl, beat 1/2 cup butter with 3/4 cup sugar until light and fluffy. Beat in eggs, and stir in vanilla and lemon zest. Fold in dry ingredients alternately with milk. Fold in blueberries. Remember, fold gently, don't stir. Spoon batter into prepared cups.
Combine 2 tablespoons flour, 5 tablespoons sugar ,and 1/2 teaspoon cinnamon in a small bowl. Cut in 2 tablespoons butter with fork or pastry blender until mixture resembles course crumbs. Sprinkle over batter in muffin cups.
Bake in the preheated oven for 20 to 25 minutes, or until a toothpick inserted in center of a muffin comes out clean. Cool in pans on wire rack. These muffins freeze really well, and re-heat in the microwave successfully.


I made the following changes to the ingredients:

whole wheat flour instead of white
2 cups frozen blueberries (I still did the flour trick to keep them from turning the batter blue)
1/2 cup sugar
1/4 cup butter (1/2 stick)
1/2 t lemon zest
a squirt of fresh lemon juice
1/2 cup plain yogurt
1/4 cup applesauce

All other ingredients were kept the same. I did use skim milk. Although the recipe doesn't specify what kind of milk to use, baking recipes usually call for whole milk.

The muffins turned out great and everyone at our Wednesday baby playgroup gave them a thumbs up! :)