In a slow cooker, add all the ingredients listed under "for the filling". Stir to combine.
In a separate bowl, combine all the ingredients listed under "for the topping". Stir well to combine. Add the mixture to the slow cooker, covering the apples completely.
Cook on low for 2-3 hours, or until apples are very soft. Optional: place a double layer of paper towels under the lid of the slow cooker as it cooks to encourage a crispier topping while still retaining moisture in the apples.
Serve with whipped cream or ice cream of choice. Enjoy!