In the bowl of a food processor, process pumpkin cookies and pecans until finely ground. Set aside. (You may have to do this batches if you have a smaller food processor.)
In a large bowl, sift together powdered sugar, salt and cinnamon. Stir into cookie and nut mixture until thoroughly combined.
Combine rum and maple syrup in a small bowl, then add to cookie mixture. Mix well.
Chill in the refrigerator for 30 minutes.
Melt dark chocolate and set aside to cool slightly. (Not too much, it should be warm to the touch, but not hot).
Scoop out portions and roll into balls.
Use a fork to lower into chocolate and turn to coat all over, then lift out of bowl with fork, dragging the bottom of the tines across the edge of the bowl to remove any excess chocolate.
Place on parchment-lined baking sheet, cover with sprinkles, and let them sit at room temperature for about an hour to allow the chocolate to set.
Video
Notes
How to toast nuts
Place pecans on a baking sheet and roast at 350°F / 177°C for 6 - 8 minutes, or until fragrant and slightly browned. Remove from oven and set aside to cool.