Step 1In a medium bowl, whisk together the oats, flour and granulated and brown sugars. Using your fingers, mix the butter into the dry ingredients until the mixture is combined and resembles small peas. Set aside.
Step 1Heat the oven to 350 degrees. In a large bowl, toss the blueberries with the sugar, flour, heavy cream, orange juice and zest.
Step 2Place the filling into an 8-inch square baking dish or 2-quart gratin dish, and sprinkle over the crumble topping.
Step 3Bake until the crumble topping is golden brown and the filling is bubbly, 30 to 35 minutes. Remove from the oven and place on a rack to cool slightly.