Preheat oven to 350 degrees.
Add peeled and chopped apples to a bowl with maple syrup, lemon juice, water and cinnamon. Toss to coat apples completely.
Pour into a greased 8x8 or 9x9 baking dish (I used coconut oil spray).
To a bowl add all of the topping ingredients. Use your hands to mix until everything is well-combined and crumbly. Pour on top of apple mixture.
Bake for 45 minutes, covering halfway through with foil to avoid over-browning the crumble topping.
Best served warm with ice cream. Enjoy!