In a small bowl, stir together 1 cup cooled espresso and 2 tablespoons granulated sugar until the sugar dissolves. Set aside.
In a large mixing bowl, beat 1 cup of cold heavy whipping cream, ½ cup of powdered sugar, and 2 teaspoons of pure vanilla extract until stiff peaks form. The whipped cream should hold its shape and look thick and smooth.
In a separate bowl, add (1) 8-ounce tub of mascarpone cheese, 1 cup pumpkin purée, 1 teaspoon ground cinnamon, ¼ teaspoon ground nutmeg, ¼ teaspoon ground ginger, and a pinch of kosher salt. Mix gently until smooth and fully combined. Then add ½ cup powdered sugar and stir into the pumpkin mixture.
Add ½ cup of the prepared whipped cream into the pumpkin mascarpone mixture and fold it in gently. Add the remaining whipped cream and continue folding just until combined. The mixture should be light and fluffy.
Working one at a time, quickly dip each ladyfinger into the espresso mixture. Do not let them sit or soak. Line the bottom of an 8 x 8-inch baking dish with the dipped ladyfingers.
Spread half of the pumpkin mascarpone cream evenly over the ladyfingers using a spatula.
Repeat with another layer of dipped ladyfingers, then spread the remaining mascarpone cream over the top and smooth it out evenly.
Spread the remaining ½ cup whipped cream evenly over the top as the final layer. Cover and refrigerate for at least 6 hours, but overnight is best for the cleanest slices and best flavor.
Right before serving, dust the top evenly with unsweetened cocoa powder. Slice and serve chilled.