Reduce the apple cider: Stirring occasionally, boil the apple cider in a small saucepan over medium-high heat until reduced to 1/2 cup. Start checking at 15 minutes and cool for 10 minutes before using.

Preheat oven to 350°F (177°C). Line baking sheets with parchment paper or silicone baking mats. Set aside.

Whisk the flour, baking powder, baking soda, cinnamon, ginger, nutmeg, and salt together in a large bowl.

In another large bowl, beat the butter, granulated sugar, and brown sugar together on medium-high speed until creamed, about 1 minute.

Add the oil, applesauce, eggs, and vanilla extract and beat on high speed until combined, about 1-2 minutes.

Add the dry ingredients to the wet ingredients, pour in the reduced apple cider, then mix on low until completely combined.

Using a medium cookie scoop, scoop mounds of batter, about 1 and 1/2 Tablespoons each, onto prepared baking sheets about 3 inches apart.

Bake for 12-14 minutes or until the edges are very lightly browned and the tops spring back when lightly touched.

Remove from the oven and allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.

Make the filling: Beat the butter on high speed until smooth and creamy, about 2 minutes.

Add the confectioners’ sugar, cinnamon, nutmeg, ginger, apple cider, and vanilla extract, then beat on medium speed until combined.

Pair the cookies up based on size. Spread or pipe the frosting onto the flat side of one cookie and sandwich with the other.