Spread one half of each whoopie pie with about 2 tablespoons of filling (use more or less as desired).
Place the other whoopie pie half on top of the filling.
Sprinkle the fall-themed sprinkles around the outside of the filling (optional).
Store in an airtight container in the refrigerator.
You can make these ahead of time and assemble them right before serving. Store the whoopie pie halves in an airtight container at room temperature and the filling in the refrigerator. Remove the filling from the refrigerator about 15-20 minutes prior to assembly to soften a little.