Preheat oven to 350°F (175°C).
Slice the French bread into 1-inch thick slices.
In a large bowl, whisk together eggs, milk, heavy cream, granulated sugar, vanilla extract, cinnamon, nutmeg, and salt.
Arrange bread slices in a greased baking dish.
Pour the egg mixture over the bread slices, ensuring they are well-coated.
In a saucepan, melt butter, brown sugar, and corn syrup over medium heat until smooth.
Pour the butter mixture over the bread and egg mixture.
Bake for 45 minutes or until the top is golden and the mixture is set.