Preheat the oven to 350 degrees.
Line a baking sheet with parchment paper.
Beat the cake mix, oil, and eggs in a medium bowl, or bowl of a stand mixer, until a dough forms.
Use a cookie scoop to gather dough, then drop onto a baking sheet.
Top with sprinkles, and flatten slightly to push them into the dough.
Transfer the baking sheet to the oven and bake for 10 minutes, remove and allow to cool for a few minutes, then transfer to a wire rack to cool completely.
Add frosting and marshmallow fluff to the bowl, then stir in the food coloring until a solid pink color has formed.
Then add the whoopie pie filling to a piping bag and snip off the tip. Pipe frosting into the center of 12 of the cookies, then top with another cookie, and gently push them together slightly.Be sure your cookies are completely cooled or the filling will ooze out everywhere and be a big mess!