Easy Overnight French Toast

Bahan-bahan (8 porsi)

• ⅓ cup melted butter
• ⅓ cup brown sugar (packed)
• 1 loaf french bread ( sliced 1" thick)
• 12 eggs ( beaten)
• 1 ½ cups milk
• 1 tablespoon vanilla extract
• 2 tablespoons maple syrup ( or ½ teaspoon maple extract)
• 2 teaspoons cinnamon (divided)
• ⅓ cup chopped walnuts (or pecans)
• whipped cream (for serving, optional)