01 -
Grease the liner of a 3 to 5-quart oval slow cooker.
02 -
Peel and slice apples thinly and add to slow cooker. Toss apple slices with cornstarch or tapioca flour until evenly coated. Pour sweetened condensed milk over slices and mix with a spoon.
03 -
In a large mixing bowl, combine brown sugar, oats, flour, cinnamon, nutmeg, vanilla, and butter. Mix until crumbly with a fork.
04 -
Sprinkle the topping evenly over the apple mixture in the slow cooker.
05 -
Cover and cook on low for 6-7 hours or high for 3-4 hours.