Preheat your oven to 350 degrees Fahrenheit.
This temperature sets the perfect environment for baking the apple crisp to perfection.
Combine your sliced apples, sugar, water, and lemon zest in a large bowl.
Mix well so that the apples are evenly coated.
In another bowl, mix the flour, oats, light brown sugar, cinnamon, and nutmeg.
Cut the butter into small pieces and add this to the mixture.
Ensure everything is well combined.
Spread the apple mixture evenly into a greased baking dish.
Top the apples with the oat mixture, ensuring an even spread.
Bake in the preheated oven for about 45 minutes or until the top is golden brown and the apples are tender.
Let it cool slightly before serving.