beat eggs, add in milk, vanilla and cinnamon and stir together.
Tear challah (or bread of choice) into golf ball sized pieces and toss into egg mixture. Stir until all chunks of bread have a chance to get soaked.
Cover mixture with plastic wrap or airtight equivalent and place in fridge overnight (or at least 3 hours)
When ready to cook, spray the inside of your slow cooker (or liner if you use a slow cooker liner) with non-stick spray.
Pour mixture into slow cooker and cook 4-5 hours on low or 2 hours on high (depending on how hungry you are!). I suggest putting a paper towel draped across the top of the pot, but under the lid, to help absorb extra moisture. According to the American Egg Board,French toast should reach an internal temperature of 165°F to be considered fully cooked and safe to eat.