Lightly grease an 8-inch square pan or a 10-inch cast-iron skillet with butter. Rinse the berries, drain well, and place them in a small bowl. Sprinkle with sugar, cornstarch, and cinnamon. Stir to coat.
18 oz. fresh blueberries , ¼ cup granulated sugar, 1 tablespoon cornstarch, ¼ teaspoon cinnamon
In a separate bowl, combine the oats, coconut, flour, brown sugar, and butter. Stir with a fork to create a streusel-like topping.
1 cup old-fashioned rolled oats, ½ cup sweetened flaked coconut , ⅔ cup all-purpose flour, ¼ cup light brown sugar, ½ cup (1 stick) unsalted butter, melted
Scoop half the topping into the prepared pan (see note). Lightly press to cover the bottom of the pan. Pour the berries over the crust, spreading them evenly across the pan. Sprinkle with the remaining crisp topping mixture. If you prefer, all of the topping mixture can be piled on top of the crisp.
Bake for 25 to 28 minutes, until golden brown. Let cool at least 10 minutes before scooping into bowls.
Notes
Gluten-free: To make this recipe gluten-free, use ⅔ cup brown rice flour instead of all-purpose flour.
Berry alternatives: Frozen blueberries may be substituted for the fresh berries in this recipe. Blackberries and raspberries work well also. If you are using frozen berries, add two tablespoons of water and an additional 2 tablespoons of sugar to the fruit mixture.
Make ahead: Prepare the crisp ahead of time as instructed but don't bake it. Cover and refrigerate the unbaked crisp up to one day in advance. Remove it from the fridge while the oven preheats, uncover, and bake as directed. It may take an additional five minutes or so. If you want to freeze the unbaked crisp, wrap it well, and freeze for up to a month. Bake the frozen crisp at 350°F for 50 to 60 minutes.