Baked French Toast

1 (13- to 14-inch-long) loaf soft supermarket Italian bread

1/2 stick (4 tablespoons) unsalted butter, softened

2 large eggs

1 2/3 cups whole milk

1/4 teaspoon salt

3 tablespoons sugar (or more)

Accompaniment: maple syrup

Butter a 13-by-9-inch glass-baking dish. Cut twelve 1-inch-thick diagonal slices from bread (reserve ends for another use). Generously butter one side of each slice and arrange slices buttered sides up in one layer in buttered dish, squeezing them slightly to fit if necessary.

Whisk together eggs, milk, and salt in a bowl until well combined, then pour evenly over bread. Refrigerate, covered, until bread has absorbed all of the custard, at least 1 hour (time may vary depending on bread). The soaked bread can be refrigerated for up to 24 hours. When ready to bake, bring soaked bread to room temperature.

Put a rack in middle of oven and preheat oven to 425° F. Sprinkle bread with sugar. Bake until bread is puffed and top is golden, 20 to 25 minutes. Serve immediately, with maple syrup.