Serves 8

8 cups fresh or frozen blueberries
1/3 cup sugar
Zest and juice from one medium lemon
3 tablespoons flour
1 tablespoon cornstarch
½ cup rolled oats
1/3 cup whole wheat pastry flour
1/3 cup packed brown sugar
½ teaspoon ground ginger
4 tablespoons unsalted butter, frozen

Preheat the oven to 350 degrees. In a large bowl, add blueberries, sugar, lemon zest, lemon juice, flour, and cornstarch. Mix to coat the blueberries. Pour into a 9-inch pie pan with 2-inch high sides.

In a medium bowl, mix together rolled oats, whole wheat pastry flour, brown sugar, and ground ginger. Grate the butter over the dry ingredients using the largest holes on a box grater. Work the butter into the dry ingredients using your fingertips until the mixture starts to hold together and is no longer dry. Sprinkle evenly over the blueberries.

Bake in the oven 55 minutes to an hour until the crumble is nicely brown and filling is bubbly. Let cool slightly before serving.