Preheat the oven to 350 degrees. Grease a 9x14 baking dish with coconut oil or spray with cooking spray.
Combine the apples, orange and lemon zests, orange and lemon juices, ¼ cup maple syrup, and 1 teaspoon cinnamon in the baking dish, stirring well.
To make the topping, combine the oat flour, whole oats, salt, 1 teaspoon cinnamon, ⅓ cup maple syrup, and melted coconut oil. Stir until well combined and crumbly. Scatter evenly over the apples.
Place the crisp on a sheet pan lined with foil and bake for 50-60 minutes, until the top is brown and the apples are bubbly.
Notes
Make sure the oat flour and whole oats are labeled gluten-free for gf diets.
Any apple works in this crisp, but I typically use a mix of sweet and tart apples for the best flavor; my go-to combo is half Honeycrisp or Pink Lady for sweetness and half Granny Smith for that tart bite that keeps it from feeling cloying.