If the bread is very fresh and soft, leave the slices uncovered for 30 to 60 minutes to dry slightly. Slightly stale bread absorbs the custard more effectively without becoming mushy.

Whisk the eggs, whole milk, maple syrup, vanilla, cinnamon, and salt in a shallow bowl or baking dish until the mixture is smooth and evenly combined. The cinnamon should be distributed throughout rather than sitting in dry patches.

Place one or two bread slices in the custard at a time. Soak for about 20 to 30 seconds per side, turning carefully so both sides are coated. The bread should feel saturated but still hold its shape.

Heat a 10- to 12-inch nonstick skillet or griddle over medium heat. Add half of the butter and let it melt until foamy but not browned.

Place the soaked bread in the skillet without crowding the pan. Cook for 2 to 3 minutes, until the underside is golden brown and the edges begin to look set.

Turn the slices carefully with a wide spatula: Cook for another 2 to 3 minutes, until the second side is golden brown and the center feels set but still tender. If the bread is browning too quickly, reduce the heat to medium-low.

Transfer the finished French toast to a plate: Add the remaining butter to the skillet and repeat with the remaining bread and custard.

Serve immediately with optional maple syrup, powdered sugar, or fresh berries.