1. Preheat the oven to 350 degrees Fahrenheit. Line a large baking sheet with parchment paper. Set aside. 2. In the bowl of a stand, cream together the butter and brown sugar together for 3 minutes. Add in the vanilla, molasses and eggs. Mix on medium speed for 1 minute then scrape the sides and bottom of the bowl to ensure everything is combined. 3. Add in the flour, quick cooking oats, baking soda and salt. Mix until fully combined. 4. Using a medium cookie scoop, scoop the cookies 2 inches apart on the baking sheet. Bake for 8-10 minutes or until the edges of the cookies just start to turn brown. 5. Allow to cool completly before filling the cookies. 6. For the filling, add the butter, marshmallow cream, powdered sugar, salt and milk together in a stand mixer bowl, mix until smooth and creamy. 4-5 minutes. Fill half of the cookies with the cream and top with another cookie. Enjoy!