Preparation

• Arrange a rack in the middle of the oven and heat to 300°F.
• Fit a wire rack inside a rimmed baking sheet. Place the bread in a single layer on the rack. Bake, flipping halfway through, until dry to the touch on both sides, about 15 minutes total. Remove from oven and let cool 5 minutes. Meanwhile, make the custard.
• Place milk or cream, eggs, maple syrup, vanilla extract, ground cinnamon, and salt in a measuring cup or bowl. Whisk until fully combined. Pour into a baking dish.
• Add slices of challah in a single layer. Soak, flipping once, until drenched but not falling apart, 1 to 2 minutes per side. Return to wire rack and repeat with remaining slices.
• Melt 2 tablespoons of butter in a nonstick skillet over medium heat. Add soaked challah slices and cook until the bottoms are golden-brown and crispy, 3 to 4 minutes. Flip and brown the other side for about 3 minutes more. Add remaining butter as needed.
• Serve warm with more maple syrup.