1/2 cup heavy cream, very cold
1/4 cup sugar
1/3 cup mascarpone cheese
3/4 cup pumpkin purée heaping
1/4 teaspoon pumpkin pie spice
8 ladyfingers, halved crosswise
2 shots espresso (about 3 ounces)
1 teaspoon rum
4-5 amaretti cookies, crushed
Combine heavy cream and sugar in a medium bowl. Beat mixture with a hand mixer, gradually increasing speed from low to medium-high, until stiff peaks form. Add mascarpone, pumpkin and pumpkin pie spice and continue beating until mixture is smooth. Set aside.
Mix rum into espresso. Quickly dunk four ladyfinger halves into the espresso mixture, placing two halves each into two small glasses. Top each with a small amount (about 1/6) of filling. Repeat process twice more, using three ladyfinger halves each time.
Cover and refrigerate overnight. When ready to serve, top each tiramisu with crushed amaretti and serve immediately.