In a large mixing bowl, combine the room-temperature mascarpone cheese, pumpkin puree, powdered sugar, vanilla extract, and pumpkin pie spice. Use a whisk or an electric mixer to blend the ingredients until the mixture is smooth and creamy. Ensure there are no lumps of mascarpone left.
In a separate chilled bowl, beat the heavy whipping cream until stiff peaks form. Be careful not to over-beat, or it will turn into butter. Once the cream is stiff, gently fold it into the pumpkin mascarpone mixture using a spatula. This keeps the filling light and airy.
Pour the cooled coffee or espresso into a shallow bowl. Take each ladyfinger and dip it quickly into the coffee. You want them to be moist but not soggy, as they will continue to soften as they sit in the cups. Depending on the size of your cups, you may need to break the ladyfingers in half.
Place a layer of coffee-soaked ladyfingers at the bottom of each glass or ramekin. Spoon a generous layer of the pumpkin cream mixture over the cookies. Repeat the layers once more, ending with a smooth layer of pumpkin cream on top.
Cover the cups with plastic wrap and refrigerate for at least 2 to 4 hours. This allows the ladyfingers to soften completely and the flavors to meld together perfectly. For the best texture, overnight chilling is recommended.
Just before serving, dust the tops of the cups with cocoa powder or a sprinkle of extra pumpkin pie spice. This adds a professional finish and a boost of flavor.