Blueberry Breakfast Bars

adapted from smitten kitchen's Raspberry Crumb Breakfast Bars, which she got from New Frontiers in Baking from the Baked Bakery in Red Hook, Brooklyn:

I used half the sweetener. Lime, because I had it. Used whole grain flours plus flaxseed meal. Very yummy. Next time will also reduce butter. Delicious, but too fattening for my butt.

For the crust and crumb:
1/2 c. whole wheat flour
1/2 c. rye flour
1/2 c. wheat germ
2 T. flaxseed meal
1/2 c. firmly packed dark brown sugar
1 1/4 cups rolled oats
3/4 teaspoon salt
3/4 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon cinnamon
3/4 cup (1 1/2 sticks) unsalted butter, cut into 1-inch pieces

For the filling:
2 T. light agave nectar
1/2 teaspoon cinnamon
2 tablespoons whole wheat flour
1 pound blueberries, frozen
1/4 cup fresh lime juice
2 tablespoons unsalted butter, melted and cooled

Make the crust and crumb: Preheat the oven to 350°F. Butter the bottom and sides of a 9-by-13-inch glass or light-colored metal baking pan. Put a long piece of parchment paper in the bottom of the pan, letting the parchment extend up the two short sides of the pan and overhang slightly on both ends. (This will make it easy to remove the bars from the pan after they have baked.) Butter the parchment.

Put the flour, brown sugar, oats, salt, baking powder, baking soda, and cinnamon in a food processor. Pulse in short bursts until combined. Add the butter and pulse until loose crumbs form.

Reserve 1 - 1 1/2 cup of the mixture and set aside. Pour the rest of the mixture into the prepared pan and use your hans or the back of a large wooden spoon to push the crust into an even layer at the bottom of the pan. The crust should touch the sides of teh pan. Bake until golden brown, 12 to 15 minutes. Transfer to a wire rack and let the crust cool. Keep the oven on while you make the filling.

Make the filling: In a medium bowl, whisk the cinnamon and flour together. Add the raspberries, agave nectar, lime juice and butter and use your hands to toss gently until the raspberries are evenly coated.

Assemble and bake the bars: Spread the blueberry filling evenly on top of the cooled crust. Sprinkle the reserved crust mixture evenly on top of the filling.

Bake for 35 to 45 minutes, rotating the pan every 15 minutes, until the top is golden brown and the filling starts to bubble around the edges.

Transfer to a wire rack to cool completely, then cut into squares and serve. The bars can be store in the refridgerator in an airtight container for up to two days.