Adjust an oven rack to the middle position and heat the oven to 200 degrees. Arrange the bread on a wire rack set over a baking sheet and bake until slightly dry, about 15 minutes.
Heat your skillet to 350 degrees or a pan over medium heat.
While the bread is in the oven, melt the butter and whisk it together with the milk, egg, sugar, vanilla, maple, cinnamon, nutmeg, and salt in a medium bowl. Slowly whisk in the flour until the mixture is smooth. Pour the batter into a large shallow dish.
