In a saucepan placed over medium low heat, mix together the marshmallows, pumpkin, butter and spices, stirring and scraping regularly with a rubber spatula until it melts—about 5 – 7 minutes.
Remove it from the heat and let it cool completely.
While you wait for the pumpkin to cool, put the wafers into a big sealable bag and thwack them with a rolling pin until they’re broken up into a fine crumb.
Dump the dark rubble into a bowl with the mini semi-sweet chocolate chips. Pour over the cooled melted butter and toss everything to combine.
In the bottom of each of your 4-ounce glasses (8 in total) and lightly press it down into the bottom (I use a large shot glass for this). Set these aside.
Once the pumpkin is cooled completely, remove the cardamom pod. Whip the cream and powdered sugar with an electric mixer over medium-high speed for about 3 – 5 minutes, or until you have stiff peaks.
Transfer the pumpkin mixture to a large, wide bowl and plop in about ¼ cup’s worth of the cream into it and beat it in to help lighten the mix. Dump the rest of the cream in and fold it all in with a rubber spatula until it’s completely combined. The best method to do this is by cutting into the center of bowl on an angle, through the cream, to the bottom. Scrape the spatula along the bottom and sides of the bowl and in a single motion fold it over the cream. Turn the bowl about a quarter-turn and repeat. Ideally, you’d do this as few times as possible because the more folding you do, the more air you will loose and you want to keep as much air trapped in there as possible.
Pour this into a piping bag and evenly distribute the mousse among each glass, piping it over the layer of cookie crumble.
Cover them with plastic wrap and refrigerate for at least 1 hour to help them set further and chill.
-If you're making the chocolate wafer recipe then you can just bake off half of the dough and freeze the rest for later (up to 3 months).
-These can be assembled up to 2 days in advance and kept, covered, in the fridge.