Grease a 9 x 13 inch baking dish with non-stick cooking spray. Arrange the slices of bread in the bottom of baking dish in 2 rows, overlapping the slices. In a large bowl, beat together eggs, milk, vanilla, salt and cinnamon. Pour mixture over bread slices, cover with plastic wrap and refrigerate for 2 hours, or overnight if using French or Challah bread. Before baking preheat oven to 350º, sprinkle a little more cinnamon on top of bread, bake uncovered for 35-40 minutes, or until center of casserole is cooked through. Serve warm topped with maple syrup, fresh sliced strawberries, blueberries, bananas or your favorite toppings.
NOTE: You can also use a loaf of French or Challah bread, cut diagonally in 1 1/2 inch slices, it's just my preference to use a healthier whole grain bread.