In a bowl, beat the whipping cream, ¾ cup of powdered sugar, and the vanilla extract with a hand mixer or stand mixer fitted with the whisk attachment until it forms peaks. Place in the refrigerator.
In another bowl, beat the cream cheese with the remaining powdered sugar until smooth.
Add in the pumpkin purée, pumpkin spice, and cinnamon. Mix until combined, making sure to scrape the bottom and sides of the bowl.
Fold in about ⅔ of the whipped cream, reserving the rest for topping. Transfer the mousse to the fridge while working on the crust.
In another bowl, combine the graham cracker crumbs, granulated sugar, and melted butter. Mix together with a fork until evenly moistened. Divide this mixture evenly between 8 individual serving cups or bowls.
Spoon or pipe the mousse into the dessert cups. Transfer to the fridge for 1 hour to set up.
Top with the reserved whipped cream and sprinkle with additional graham cracker crumbs, pumpkin spice, and/or chopped pecans before serving.