Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, and salt. Set aside.
In a large mixing bowl, cream the softened butter and brown sugar together until light and fluffy, about 2-3 minutes.
Beat in the egg and vanilla extract until well combined.
Gradually add the dry ingredients to the wet mixture, alternating with the apple cider, starting and ending with the dry ingredients. Mix until just combined.
Using a tablespoon or cookie scoop, drop rounded tablespoons of dough onto the prepared baking sheet, leaving about 2 inches between each cookie.
Bake for 12-15 minutes, or until the cookies are set and lightly golden. Allow them to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.
Once cooled, spread a generous amount of caramel sauce on the flat side of one cookie and sandwich it with another cookie. If desired, dust the tops with powdered sugar before serving.