Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.

In a large mixing bowl, combine softened unsalted butter and granulated sugar. Beat on medium speed for 2-3 minutes until light and fluffy.

Add the eggs one at a time, mixing well after each addition. Then, pour in the fresh apple cider and mix until fully incorporated.

In a separate bowl, whisk together all-purpose flour, baking powder, cinnamon, and nutmeg. Gradually mix this dry mixture into the wet ingredients until just combined.

Drop heaping tablespoons of dough onto the prepared baking sheets, spacing about 2 inches apart.

Bake for 10-12 minutes until lightly golden and springy to touch.

Let cool on the baking sheets for a few minutes before transferring to wire racks to cool completely.

In a medium bowl, beat together softened cream cheese, powdered sugar, and vanilla until smooth. Gradually add milk until spreadable.

Spread frosting on the flat side of one cooled whoopie pie half and sandwich with another half.

Optional: Roll the edges in a mixture of sugar and cinnamon for extra flavor.