01 - In a small saucepan, melt the butter with brown sugar and corn syrup over medium heat, stirring until smooth and bubbling. Pour into the bottom of a 9x13-inch baking dish and spread evenly.
02 - Arrange the bread slices in a single layer over the caramel, slightly overlapping if needed to fit.
03 - In a mixing bowl, whisk together eggs, milk, cream, sugar, vanilla extract, and salt until completely smooth and combined.
04 - Pour the custard mixture evenly over the bread. Gently press down on the bread slices to help them absorb the liquid.
05 - Cover the dish tightly with plastic wrap and refrigerate for 8–12 hours to allow the bread to fully absorb the custard.
06 - Preheat oven to 350°F. Remove the dish from the refrigerator and let it sit at room temperature while the oven heats.
07 - Bake uncovered for 30–35 minutes until the French toast is puffed, golden brown, and the custard is completely set.
08 - Remove from oven and let cool for 5 minutes before adding the sugar topping.
09 - Sprinkle the granulated sugar evenly over the top. Using a kitchen torch, brûlée the sugar until melted and caramelized. Alternatively, place under a broiler for 1–2 minutes, watching closely to prevent burning.
10 - Serve warm, spooning any extra caramel sauce from the bottom of the dish over each portion.