Whisk together milk, eggs, vanilla, brown sugar, cinnamon, and salt. Pour into the bowl. Make sure the bread is completely covered in the mixture. Refrigerate for at least 2-4 hours.
When ready to cook, lightly grease the inside of a slow cooker. Add the mixture in an even layer and cover. Cook on Warm for 8 to 9 hours.
If the casserole has a lot of uncooked egg on top after 8 hours, turn the slow cooker to High for 30-60 minutes until done. Note that there will be some liquid on the edges from condensation and the melted sugar.
Serve with maple syrup or powdered sugar if desired. Enjoy!
*This works best with day old bread, so it can really absorb the mixture. Do not use a soft or white bread as it will likely not hold up well while soaking.*Use an unsweetened dairy free milk for a dairy free version.*Use gluten free bread for a gluten free version.*For egg safety, be sure you cook your eggs to at least 160*F. Some slow cookers do not get that hot on the warm setting. You can use pasteurized shell eggs because they have been heat-treated but not cooked to destroy bacteria.
Recipe from Living Well Kitchen https://blog.memeinge.com/slow-cooker-french-toast-casserole/