1 cup gingersnap cookie crumbles, plus 6 whole cookies for garnish
In a standing mixer with a whisk attachment, cream the whipping cream and vanilla crème fraîche together until stiff peaks form. Set aside about 1/2 cup of the mixture for topping the mousse later.
In a separate bowl, combine pumpkin puree, maple syrup, spices, and salt. Carefully fold pumpkin mixture into whipped cream mixture using a spatula.
Place mousse into a piping bag with a large round tip. Pipe mousse into 6 ramekins, stopping about 1/3 of the way up. Sprinkle in about 2 tablespoons of gingersnap crumbles, then pipe the rest of the way up the ramekin.
Sprinkle about 1 tablespoon of gingersnap crumbles on top of the mousse, then spoon about 2 tablespoons of the reserved whipped cream mixture from earlier. Garnish with a whole gingersnap cookie. Refrigerate up to 3 days in fridge.