Whisk together pumpkin, yogurt, all but 1 Tbsp sugar and spices.
In another bowl beat cream, slowly adding remaining 1 Tbsp of sugar, until stiff peaks. Stir in vanilla then fold in pumpkin mixture. Reserve some whip cream for topping.
Crumble 8 of the cookies into small-medium sized chunks.
To serve, spoon mousse into 8 cups then top with a dollop of whipped cream, some crushed cookies and one whole cookie.