In the bowl of a food processor, combine the ricotta, mascarpone, confectioners' sugar, pumpkin puree, vanilla, cinnamon, ginger, and nutmeg. Puree until smooth. Transfer the mixture to a serving bowl. In a separate bowl, whip the heavy cream until stiff peaks form. Add half of whipped cream to ricotta mixture and fold until combined; then add the remaining whipped cream and fold until combined. Stir in the chocolate chips. Garnish with pistachios or chocolate chips, if desired. Serve with pizzelle, graham crackers, apple slices, or fried flour tortilla chips dusted lightly with cinnamon.