Overnight French Toast Casserole Recipe

Ingredients (9)

• 4 tablespoons butter (room temperature)
• 12 slices ​French bread (3/4-inch-thick)
• 6 large eggs
• 1 1/2 cups​ milk (or half-and-half)
• 1/4 cup sugar
• 2 tablespoons maple syrup
• 1 teaspoon vanilla
• 1/2 teaspoon salt
• Garnish: confectioners sugar (to taste)