Preheat oven to 350°F. Line 2 large baking sheets with parchment paper. Set aside.
Using an electric mixer, cream together butter, shortening, brown sugar and granulated sugar. Beat for 2 minutes until fully combined.
To the creamed mixture add eggs, molasses and vanilla. Beat until creamy for 1-2 minutes, stopping to scrape the sides of the bowl periodically.
Meanwhile, in a separate bowl, sift together oatmeal, flour, baking soda, salt, cinnamon and clove using a whisk. Lower the speed of the mixer and gradually add to the creamed ingredients. Scrape the sides of the bowl, as needed. The dough will be thick.
Using a medium ice cream scoop or Tbsp, divide the dough equally into mounds. (approximately 2 Tbsp of dough each) Leave at least 3 inches between to allow for spreading.
Bake in batches for 10-12 minutes, or just until the edges are lightly golden. Cool for 5 minutes on the pan, then carefully move to a cooling rack to cool completely. These cookies are tender when warm.
To make the filling: Using an electric mixer, cream butter and shortening with vanilla. Lower the speed of the mixer gradually adding the powdered sugar and 2 Tbsp cream. Once combined, Add marshmallow cream, then beat on high for 2 minutes.
Divide filling evenly among 18 cookies. Top each with a matching size cookie.
May store at room temperature for 1 day. For longer storage, keep chilled in an airtight container with wax paper between layers. Bring to room temperature for serving.