In a small heavy saucepan melt butter with brown sugar and corn syrup over moderate heat. Stir until smooth and pour into a 13 by 9 by 2 inch baking dish.
Wisk together eggs, half-and-half cream, vanilla,and amaretto in a bowl until combined well. Toss bread cubes in the egg mixture before adding it on top of the sugar mixture. Arrange bread in the baking dish and squeeze them slightly to fit. Chill bread mixture, covered, at least 8 hours and up to 1 day.
Preheat oven to 350 F. and bring bread to room temperature. Bake bread mixture, uncovered, in middle of oven until puffed and edges are pale golden, approximately 35-40 minutes.