Bountiful Blueberry Bars

Why I Love This Recipe
This recipe is my own, based on my mother's jam bars. I wanted to make something with fresh fruit instead of jam. The whole wheat flour adds a nice touch of whole grains. These are absolutely scrumptious.
Ingredients You'll Need
2 Cups flour
1 Cup whole wheat flour
1 Cup sugar, divided
1 tsp. apple pie spice
1 tsp. vanilla
1/2 tsp. salt
1 Cup room temperature butter
4 cups (2 pints) fresh or thawed, frozen blueberries
2 Tablespoons lemon juice
Coarse grain sugar for garnish
Directions
Preheat oven to 375 degrees. Spray an 11 x 14 or a 9 x 13 pan with nonstick spray and set aside.
In a large bowl, combine blueberries, half cup of sugar and lemon juice. Gently toss to combine and set aside.
In another large bowl, combine remaining ingredients except for coarse grained sugar. Using a pastry blender or clean hands, work the butter into the dry ingredients until you have a dough that holds together when pinched.
Divide dough evenly and press half into greased baking pan. Spoon blueberry mixture evenly over bottom crust. Sprinkle remaining crust dough evenly over blueberry layer and pat to form to crust.
Sprinkle with coarse grain sugar.
Bake for 25 minutes, or until the top crust starts to lightly brown.
Makes 12-24 bars, depending on size.