In a heavy-duty plastic zip top bag, crush the gingersnap cookies with a rolling pin or meat mallet (don’t smash into fine crumbs; cookie pieces should be around 1/2-inch in size).
Divide cookie pieces evenly in the bottom of each pots de crème.
Sprinkle evenly with chopped crystallized ginger.
Measure out 1/4 cup of the rum and set aside. Sprinkle remaining rum over the cookies and ginger (around 1 to 1 1/2 teaspoons per cup). Set aside.
Put the reserved 1/4 cup rum in the top of a double boiler (don’t put it over simmering water yet). Sprinkle the gelatin over the top and let soften for about 8 to 10 minutes (it will start to solidify but that’s okay).
While the gelatin softens, in a large mixing bowl whisk together the pumpkin, egg yolk, brown sugar, 1/4 cup sugar, orange zest, 1/4 teaspoon cinnamon, nutmeg and 3/4 teaspoon of the vanilla.
Place top of double boiler with rum mixture over simmering water and heat, stirring, just until the gelatin melts (the rum will be clear). Whisk into the pumpkin mixture.
In a large mixing bowl, whisk 3/4 cup of the whipping cream with an electric mixer until soft peaks form; fold into pumpkin mixture.
Carefully spoon into pots de crème; smooth the top.
Refrigerate about 1 hour or until set. In a large mixing bowl, whisk the remaining 1 cup whipping cream, remaining 1 tablespoon granulated sugar, remaining 1 teaspoon vanilla, and remaining 3/8 teaspoon cinnamon until stiff peaks form.
Pipe or spoon onto top of pots de crème. Sprinkle top with additional cinnamon.
Cover and refrigerate until ready to serve.