Preheat your oven to 375℉. Lightly grease an individually sized gratin dish or other small baking dish.
Prepare the Filling: In a small bowl, combine the fresh fruit, sugar, lemon juice, and gluten-free flour. Toss until the fruit is well-coated. Transfer the mixture to your prepared dish.
Make the Topping: In another small bowl, combine the gluten-free flour, brown sugar, gluten-free oats, and cinnamon. Add the dairy-free butter and use a fork to cut it into the mixture until it becomes crumbly. Sprinkle the topping evenly over the fruit filling.
Bake: Place the dish in the preheated oven and bake for 20-25 minutes, or until the topping is golden brown and the filling is bubbly.
Serve: Enjoy the crisp warm or at room temperature with a scoop of dairy-free vanilla ice cream on top.