Crème Brûlée French Toast

Melt the butter in a small saucepan over medium heat. Stir in the brown sugar and corn syrup until the mixture is smooth and begins to bubble gently, which should take about 3 to 4 minutes.
Immediately pour the hot butter and sugar mixture into a 9x13 inch baking dish, tilting the dish to evenly coat the entire bottom.
Arrange the slices of French bread in a single layer over the sugar mixture, squeezing them in snugly if necessary.
In a medium bowl, whisk together the eggs, half-and-half, vanilla extract, salt, and cinnamon until the mixture is completely smooth and uniform in color.
Slowly and evenly pour the egg mixture over the bread slices, ensuring each piece is thoroughly saturated. Gently press down on the bread with a spatula to help it absorb the custard.
Cover the baking dish with plastic wrap and refrigerate for at least 8 hours or overnight to allow the custard to fully soak into the bread.
Preheat your oven to 350°F (175°C). Remove the plastic wrap from the dish and bake for 35 to 40 minutes, until the top is golden brown and the custard is set (it should feel firm to the touch in the center).
Let the French toast stand in the baking dish for 5 minutes before inverting each slice onto a serving plate, revealing the caramelized bottom layer which now becomes the top.