In a small saucepan, heat the brown sugar, corn syrup, and butter over medium heat until the sugar dissolves. Stir to a syrupy consistency. Pour into a greased nine- by 13-inch (20- x 30-centimeter) baking pan.

Toss grated apples with vanilla sugar, lemon juice, and half a teaspoon cinnamon. Spread over the caramel in the pan.‎

Slice French bread into one-inch (two-centimeter) wide slices and lay neatly on top of the shredded apple mixture.‎

Combine remaining half a teaspoon cinnamon with the milk, eggs, vanilla, salt, and sugar and whisk well.

Pour over the French bread and sprinkle with additional cinnamon. Cover with aluminum foil and refrigerate overnight.

Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).

Place baking pan in the oven, still covered, and bake for 40 minutes. Uncover and bake an additional 15 minutes.

Use a spatula to lift out each serving. Turn over so the caramel layer is on top. Spoon up extra caramel from the pan and drizzle over French toast.