Combine eggs, half and half, vanilla, cinnamon and salt in large mixing bowl. Add challah bread pieces, gently stirring to coat bread with egg mixture. Pour into a lightly greased 10" square pan and set aside.
Melt butter and brown sugar in a small sauce pan over medium heat until combined with a smooth texture, about 5-7 minutes. Pour evenly over bread then wrap tightly with plastic wrap and place in refrigerator overnight.
Remove casserole from refrigerator, uncover and allow to rest for about 10 minutes.
Preheat oven to 350 degrees then bake for about 30-35 minutes until eggs are set and it's hot and bubbly (place aluminum foil on top if bread browns to quickly). Enjoy!
Notes
Challah is a sweet egg-based bread known for its beautiful braid and shiny finish. Once found only in delicatessens, it’s now readily available most everywhere.