Pre-heat oven to 375
Peel, core, and slice you apples into evenly sized pieces.
Add the apples to a bowl along with the lemon juice and water. Mix.
Add in the sugar, cinnamon, and vanilla and mix again.
Add the apple mixture to a 8x8 or 9x9 pan then set it aside while you make the topping.
In a bowl, add in the oats, flour, brown sugar, salt, and cinnamon and mix together.
Add in the butter and mix well until crumbly.
Evenly add the topping onto the apples
Bake at 375 for 40-45 minutes or until golden brown and apples are bubbling.
Serve warm with a scoop of vanilla ice cream if wanted