Preheat oven to 350 degrees F.
Whisk together flour, baking powder, baking soda, and salt. Set aside. In another bowl, toss together oats, dried cherries, toasted pecans, and chocolate chips. Set aside.
In the bowl of a stand mixer, cream together butter and sugar until smooth. Add the egg and vanilla. Mix until incorporated. With the mixer on low, slowly add in the dry flour mixture in three additions. Mix until just blended. Fold in oat mixture until evenly distributed.
Use a 1 oz ice cream scoop or 2 tablespoons to scoop out balls of dough. Arrange dough onto a parchment lined sheet tray. You should end up with 36 pieces. Gently flatten each ball of dough with the palm of your hand.
Bake cookies for 12 minutes. Rotate the sheet trays and then back for another 6 minutes until cookies are golden brown and the center is still slightly soft. Let cookies cool on sheet trays.
Once cookies have cooled, spread 1 tablespoon of marshmallow fluff on the bottom of 18 cookies. Pair the remaining 18 cookies with similar size/shape bottom cookies. Sandwich the cookies together.
To make the chocolate drizzle sauce, bring the cream to a boil. Place chopped chocolate and honey in a medium bowl. Pour hot cream over chocolate. Let mixture stand for 1-2 minutes. Cover with plastic wrap to kept warmth inside. Then stir mixture until chopped chocolate has melted and the mixture is smooth.
Drizzle chocolate over prepared cookie sandwiches and enjoy.