In the same food processor or high-powered blender (no need to wash between - I used my Vitamix, but most powerful blenders should do the job), combine all of the filling ingredients except for the cacao powder and 1 tablespoon maple syrup and blend for about 2 minutes, or until the mixture is silky smooth and creamy. Scrape down the sides as necessary.
Pour half of the filling into a separate bowl. Add the cacao powder and remaining one tablespoon of maple syrup to the other half of the pumpkin mixture, still in the blender. Blend it in until smooth.