Whole-Wheat Blueberry Bars

We went blueberry picking this last Saturday and came home with 16 lb of blueberries. The girls and I had the greatest time. I love picking blueberries!  Needless to say with so many blueberries I went looking for blueberry recipes. This one is so, so good!

Crust

1 1/3 cups plus about 3 Tbs whole-wheat pastry flour
1/2 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
1/2 cup packed light brown sugar
2 tablespoons butter, softened
2 tablespoons canola oil
1 large egg
1 teaspoon vanilla extract

Blueberry Filling

1/3 cup Agava or 1/2 cup sugar 
2-3 tablespoons whole-wheat pastry flour
3 cups fresh or frozen blueberries
1 tablespoon lemon juice

 Preparation

1. To make crust: Preheat oven to 350°F. Coat a 9-by-13-inch baking dish with nonstick cooking spray.
2. Whisk together 1 1/3 cups + 3 Tbs whole-wheat pastry flour, baking powder, baking soda and salt in a large bowl. Beat together brown sugar, butter, oil, egg and vanilla in another large bowl with an electric mixer on high speed until smooth, making sure no lumps of brown sugar remain, about 1 minute. Add the dry ingredients and stir with a wooden spoon until well blended. (The dough will be quite firm.)
3. Transfer two-thirds of the dough to the prepared baking dish; cover the dough with a piece of plastic wrap and use it to press the dough into the bottom of the dish in an even layer. Remove the plastic wrap. Bake until puffed and golden, about 15 minutes.
4. To make the topping: Gradually work about 3 more tablespoons whole-wheat pastry flour into the remaining dough using your fingertips, until it resembles coarse crumbs.
5. To make filling: Combine blueberries and lemon juice in a medium saucepan; cook, stirring, over medium heat until the berries begin to exude juice. Add the Agava syrup and stir. 
6. Gradually add up to 3 Tbs of whole wheat flour, stir until the filling reaches a simmer and thickens.
7. Push down the higher outside edges of the baked crust with a wooden spoon; pour the hot filling over it and spread all the way to the sides of the dish. Sprinkle the crumb topping over the top. Bake until the topping is golden, 15 minutes longer.
8. Transfer the baking dish to a rack and let cool, covered with a kitchen towel to soften the crumbs slightly. Cut into 15 bars. Store at room temperature in an airtight container.