Preheat oven to 350 degrees F. Line a large cookie sheet with parchment paper; set aside. In a large bowl combine brown sugar and butter. Beat with an electric mixer on medium speed until fluffy. Add eggs and vanilla; beat until combined. Add applesauce and whipping cream; beat well. In a medium bowl combine flour, cinnamon, baking powder, baking soda, and salt. Gradually add flour mixture to the beaten mixture, beating until well mixed.
Drop batter by spoonfuls about 2 inches apart onto prepared cookie sheet. Bake in the preheated oven for 10 to 12 minutes or until edges are light brown. Transfer to a wire rack; cool.
Spread Fluffy Filling on bottoms of half of the cooled cookies. Top with the remaining cookies, bottom sides down. Serve immediately or store in the refrigerator and serve within 24 hours. If desired, garnish with apple peel ribbons.
In a medium bowl combine 1 cup butter, softened; 1/2 cup marshmallow creme; 1/4 cup whole milk; 1/4 cup all-purpose flour; and 1 teaspoon vanilla. Beat with an electric mixer on medium speed until well mixed. Gradually add 4 cups powdered sugar, 1 cup at a time, beating until well mixed and fluffy. Makes about 2 2/3 cups.