- 4 apples, peeled and thinly sliced
- 1 teaspoon lemon juice, or as needed (optional)
- 1/2 cup butter
- 2 1/2 tablespoons all-purpose flour
- 1/2 cup brown sugar
- 1/2 cup white sugar
- 1/4 cup water
- 9 eggs
- 1/4 cup milk
- 1/2 teaspoon ground cinnamon
- 1/2 teaspoon vanilla extract
- 1 loaf thick-cut bread
- 1/2 cup frozen butter
- Place apples in a bowl and drizzle with lemon juice to keep from browning.
- Melt 1/2 cup butter in a large saucepan over medium heat; remove from heat. Stir flour into melted butter until smooth. Return saucepan to low heat; stir in brown sugar, white sugar, and water until sugars dissolve and mixture is smooth, 3 to 5 minutes. Increase heat to medium; cook and stir mixture until boiling. Reduce heat to low and add apples. Simmer mixture until apples are cooked but slightly tender, 20 to 25 minutes.
- Preheat griddle to 325 degrees F (165 degrees C).
- Whisk eggs, milk, cinnamon, and vanilla extract together in a bowl. Dip bread slices into egg mixture until completely coated.
- Grease heated griddle with frozen butter. Cook dipped bread slices on the hot buttered griddle until browned, 2 to 3 minutes per side. Repeat with remaining frozen butter and dipped bread. Serve French toast with apple mixture ladled over top.