Baked Apple French Toast - Once Upon a Chef

Ingredients

• One 1-lb challah or raisin challah
• 5 large eggs
• 1½ cups half & half
• 3 tablespoons maple syrup
• 2 tablespoons bourbon ((optional; see note))
• 1 teaspoon vanilla extract
• Heaping ¼ teaspoon salt
• 4 tablespoons unsalted butter
• 4 large Granny Smith apples, (peeled and thinly sliced)
• ¼ cup + 2 tablespoons (packed) dark brown sugar
• 6 tablespoons maple syrup
• 1 teaspoon ground cinnamon
• Confectioners' sugar and/or maple syrup