Baked Challah French Toast Recipe

Ingredients

• butter for greasing
• 1.5 loaves challah, cut into 1-inch pieces
• 0.75 cup white sugar, divided
• 1 tablespoon ground cinnamon, or more to taste
• 3 cups milk
• 8 large eggs
• 1 tablespoon vanilla extract
• 1 teaspoon salt
• 1 stick unsalted butter, cut into 10 pieces