Preheat oven to 200 °C.
Combine rolled oats, flour, cinnamon, maple syrup and olive oil into a bowl and mix until combined.
To prepare the filling, combine apples, cinnamon and nutmeg in a large bowl and stir until well combined. Transfer to a 1.5 litre ovenproof dish and add water. Spoon crumble mixture over the apples. Bake for 35-40 minutes, or unti golden and apples are soft.