Over a fine mesh strainer, strain pumpkin puree of any excess liquid. Set aside
Sift the powdered sugar, cocoa powder and all the spices together. Set aside.
Add mascarpone, pumpkin puree, spices, sugar, salt and cocoa powder to mixing bowl and whisk/mix until very smooth.
In another bowl whisk heavy cream (40% fat preferred) until very stiff. You should be able to see the bowl on the bottom and/or turn it upside-down without it falling.
Slowly incorporate the whipped cream and pumpkin/mascarpone mixtures together. Using your spatula Start by adding 1/3 of the whipped cream directly into the pumpkin mixture and while turning the bowl fold over each mixture combining slowly. Continue by adding the next 1/3 of whipped cream, mix - incorporate then mix the rest.
Store in refrigerator for up to 1 week. You may transfer the mousse to a piping bag to be able to pie into waffle cones.
Optional â garnish with caramel or butterscotch sauce, and with fresh berries and fresh mint. Or simply scoop into a small bowl and enjoy!