Cut bread into 2-3 inch cubes
Spray slow cooker with non-stick spray
Press bread down into bottom of slow cooker and compress as much as you can
Pour condensed milk evenly over bread
Whisk together eggs, milk and salt and pour evenly over bread
Cover and cook on high for 2 to 2 1/2 hours
Melt caramels and cream in microwave using 30 second intervals and stirring between until smooth
Slice and serve french toast casserole topped with crème fraîche and melted caramel or as desired