Spray the inside of the slow cooker with nonstick cooking spray.
Cut (or tear) the slices of bread into chunks. Next, add all of the ingredients for the apple filling in a mixing bowl. Stir to combine. Finally, add all of the ingredients for the custard mixture in a another mixing bowl. Stir to combine.
Add half of the cut bread slices on the bottom of the crockpot. Next, add 1/2 of the apple filling followed by 1/2 of the custard mixture. Repeat layers.
Cover and cook on high 2 hours or on low 4 hours, or until bread has soaked up the liquid. Enjoy warm with additional syrup, Tru Whip, chopped nuts, or even low sugar ice cream if desired!