Preheat the oven to 350°F (175°C).

In a medium bowl, whisk together flour, baking soda, baking powder, ginger, cinnamon, nutmeg, and salt.

In a large bowl, cream the butter, brown sugar, and granulated sugar until light and fluffy.

Add the egg, molasses, and vanilla extract to the creamed mixture and beat until well combined.

Gradually mix in the dry ingredients until just combined; avoid overmixing.

Drop tablespoonfuls of the batter onto a parchment-lined baking sheet, spacing them about 2 inches apart.

Bake for 10-12 minutes, or until the edges are set but the centers are still soft.

Let them cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.

In a medium bowl, combine marshmallow fluff, cream cheese, powdered sugar, and cinnamon for the filling; mix until smooth.

Once the whoopie pies are fully cooled, spread or pipe a generous amount of filling onto the flat side of one half, then sandwich with another half.

Dust with powdered sugar if desired, and enjoy your homemade gingerbread whoopie pies!