Pour egg mixture over bread slices for a breakfast you can eat over and over

1 stick butter, melted
1 cup brown sugar
1/2 cup chopped pecans
1 loaf French bread, cut into 1 1/2-inch thick slices on the diagonal
4 eggs
1 cup whole milk or half and half
1/2 teaspoon cinnamon
1/4 teaspoon nutmeg
1 teaspoon vanilla extract