For the Apple Cider Whoopie Pies

• 2 cups apple cider reduced to 1/4 cup
• ½ cup unsalted butter room temperature, divided (6 tablespoons for the dough and 2 tablespoons melted for brushing the baked cookies)
• 1 ¾ cups flour
• ½ teaspoon salt
• 1 teaspoon baking powder
• ¼ teaspoon baking soda
• 1 ½ teaspoon cinnamon
• ¼ teaspoon ginger
• ½ teaspoon nutmeg
• ½ cup granulated sugar
• ¼ cup plus 2 teaspoons brown sugar, light or dark, packed
• ¼ cup apple butter or applesauce
• 2 eggs
• ¼ teaspoon vanilla

For the Cinnamon Sugar Coating

• 3 tablespoons butter melted
• ¼ cup sugar
• ½ teaspoon cinnamon

For the Bourbon Caramel Buttercream (optional)

• ½ cup unsalted butter room temperature
• 1 ¼ – 1 ½ cups powdered sugar, sifted (add gradually until desired consistency)
• 2 tablespoons plus 2 teaspoons Bourbon Caramel Sauce, cooled to room temperature
• 1 pinch of salt

For the Brown Sugar Cream Cheese Icing (optional)

• 4 ½ ounces cream cheese room temperature (leave at room temperature at least one hour before using)
• 3 tablespoons butter room temperature
• 2 tablespoons brown sugar, light or dark
• 2 cups powdered sugar sifted, plus more if needed
• ½ teaspoon vanilla extract
• 1 pinch salt