In a large bowl, using a blender, beat butter, brown sugar, and egg on medium speed until well blended and creamy. Add molasses and vanilla to the brown sugar mixture and continue to mix until well blended.
Sift into the brown sugar mixture the dry ingredients: flour, baking powder, baking soda, salt, ginger, cinnamon, and cloves. Carefully stir dry ingredients into brown sugar mixture until well blended. Form the dough into a ball-like form and rest at room temperature for two hours. If you need to refrigerate the dough, you can refrigerate up to 4 days. If the dough is refrigerated, bring dough back to room temperature before rolling out.
Before you begin to roll out the dough, place an oven rack in the upper 1/3 of the oven. Preheat the oven to 375° F.
Roll out the dough onto a lightly floured surface. Roll out the dough to ¼ inch thick. It seems thin but these will rise. Use about a 3-inch round cookie cutter to cut the shapes of the gingerbread cookies. Place the cookies onto a parchment covered baking sheet and bake for 8-10 minutes. Once you take the cookies out of the oven, cool on a wire rack. The cookies should be completely cool before assembling.
To prepare the filling, thoroughly blend in a mixing bowl the butter and marshmallow cream for two minutes on high speed. Add the cream and ½ of the powdered sugar to the bowl. Start on a low speed and mix for 30 seconds. Stop the blender, add the remaining powdered sugar and mix for another 30 seconds on low speed. This is so you don’t have powdered sugar flying everywhere. Once it seems safe, increase the speed on the blender until you are blending on high for about 2 minutes.
To make the Gingerbread Whoopie Pies, place about 1 tablespoon of the filling in the center of one cooled off gingerbread cookie. Spread the filling out a bit but do not spread it to the edge. Top with another gingerbread cookie and gently push down. The filling should spread out to the edges of the cookie. Enjoy!