In a large bowl, whip the heavy cream. Set this aside.
In a separate bowl, blend together the pumpkin puree, sugar, vanilla extract, and pumpkin spices. Stir in the mascarpone cheese into the pumpkin mixture, ensuring it integrates smoothly.
Gradually incorporate the whipped cream into your pumpkin and cheese mixture.
Briefly dip each ladyfinger into the coffee and arrange a layer at the bottom of your dish.
Distribute half of your pumpkin and cream concoction evenly over the layer of ladyfingers.
Repeat the process with another layer of coffee-infused ladyfingers.
Spread the remaining pumpkin mousse. Dust a fine layer of cocoa powder atop the final layer.
Cover the dish with plastic wrap and allow it to chill in the fridge for a minimum of 2 hours.