Nestled beneath a crisp topping of spiced whole-grain rye and oats, sweet-tart blackberries stew with just the lightest touch of maple syrup. They lose their form in the heat of the oven, releasing their vivid purple juices to form a humble dessert that positively sings of late summer.
Dump the blackberries in a bowl. Spoon ¼ cup dark rye flour over the berries, and then drizzle maple syrup and bourbon over them. Gently stir the berries to incorporate the flour until they're lightly coated, taking care not to smash them. Arrange the berries in a 9" x 13" baking dish.
In a separate bowl, add ¾ cup dark rye flour, cloves, cinnamon, salt, maple sugar, rolled oats and ½ cup softened butter. Work the ingredients together with your hands until they form a crumbly, stick dough.
Sprinkle the prepared blackberries with the the dough, and then drop the remaining two tablespoons of butter over the topping. Bake for 45 minutes.