Coat a 13 x 9-inch baking dish with non-stick cooking spray.
Arrange bread slices in the pan in two rows with the slices overlapping.
In a mixing bowl, combine eggs, half-and-half, milk, vanilla extract, sugar, cinnamon, nutmeg, and salt.
Pour egg mixture over the bread slices.
Cover and refrigerate overnight.
When ready to bake and serve, remove from refrigerator and pre-heat oven to 350°F.