Step 1

Arrange a rack in the center of the oven and preheat to 300 degrees F.

Step 2

Cut the bread into 8 slices about 3/4-inch thick. Arrange them in a single layer on a rimmed baking sheet (it's ok if they overlap). Bake, flipping them halfway through, until very lightly golden on both sides, about 12 minutes. Let them cool on the baking sheet until ready to use. Reduce the oven temperature to 200 degrees F.

Step 3

Vigorously whisk the eggs in a large bowl until blended and no streaks of whites remain. Add the half-and-half, sugar, vanilla, cinnamon, salt and nutmeg and whisk until completely incorporated. Transfer to a 2-quart baking dish.

Step 4

Gently press 2 slices of the toasted bread into the custard. Turn to coat and then gently press down on the bread until you feel it start to soak up the custard—this is key for a luscious, moist texture. Let the bread soak for about 1 minute per side; it should feel heavy but still hold its shape and not fall apart.

Step 5

Melt 1 tablespoon of the butter in a large nonstick skillet over medium-low heat. Cook 2 of the soaked bread slices until they are a deep golden brown, the custard has set and the insides are cooked through, 4 to 5 minutes per side. The center of the bread will puff slightly while the crust will contract, making it look puckered. You may have to alternate between medium and medium-low heat if the bread browns too quickly or not fast enough. Transfer the slices to a rimmed baking sheet and hold in the warm oven. Repeat with the remaining butter and bread.

Step 6

Serve the French toast with butter, maple syrup and a sprinkle of confectioners' sugar.