Caramel French Toast

1 stick unsalted butter
1 cup packed brown sugar
2 tablespoons corn syrup
1 loaf French bread
5 large eggs
1 1/2 cups half-and-half
1 teaspoon vanilla
1 teaspoon Grand Marnier
1/4 teaspoon salt

Melt butter with brown sugar and corn syrup in a small heavy saucepan over moderate heat, stirring until smooth and pour into a 13"x9"x2" baking dish.

Cut six 1-inch thick slices from center portion of bread, discarding end piecces. Arrange bread slices in one layer in baking dish, squeezing them slightly to fit.

Whisk together eggs, half-and-half, vanilla, Grand Marnier and salt until combined well and pour evenly over bread. Chill bread mixture, covered, at least 8 hours and up to 24 hours.

Bring dish to room temperature. Bake, uncovered, in the middle of oven preheated to 350 degrees until puffed and golden, 35 to 40 minutes. Serve immediately.