In a small saucepan over medium-low heat, combine pumpkin 3/4 cup cream, brown sugar, maple syrup, spices, salt and 1 teaspoon vanilla. Cook, whisking constantly for 5 minutes.
In a small bowl, combine water and cornstarch. Add to pumpkin mixture and bring to a boil. Continue to cook, whisking constantly for 2 minutes. Remove from heat and pour through a fine mesh strainer into a large bowl. Press plastic wrap to the top of the pumpkin mixture and allow to cool to room temperature.
When ready to continue, in a medium bowl beat 1 1/2 cup heavy cream and 1 teaspoon vanilla until still peaks form. Fold in 1/3 of whipped cream into pumpkin mixture, followed my remaining whipped cream until no streaks remain.
Spoon a portion of the pumpkin mousse into the bottom of each of your serving cups or bowls, cover with more mousse, a second layer of cookies and a final layer of mousse. Chill 2-4 hours or overnight.
If desired, top off with fresh sweetened whipped cream.