Line the bottom of an 8-inch springform pan with parchment paper. Cut 2 (3½-inch-wide) strips of parchment to line sides of pan.
In a medium bowl, stir together wafer crumbs, brown sugar, and melted butter. Press into bottom of prepared pan. Freeze until firm, about 20 minutes.
In the bowl of a stand mixer fitted with the whisk attachment, beat cream cheese and granulated sugar at medium-low speed until smooth, 1 to 2 minutes. Add cream, pumpkin, vanilla extract, cinnamon, ginger, nutmeg, allspice, and cloves; beat at low speed to combine. Slowly increase speed to medium-high, and continue to beat until stiff peaks form.
Spread 1 cup of pumpkin mixture over chilled cookie crust. Top with a single layer of 8 wafers, careful not to touch sides of pan. Top with another 1-cup layer of pumpkin mixture and 8 cookies; repeat layers 2 more times for a total of 4 layers of each. Spoon remaining pumpkin mixture over last layer of cookies.
Smooth top with an offset spatula, cover with plastic wrap, and freeze for at least 4 hours or overnight.
Remove sides from pan, and remove parchment paper.
Transfer cake to a serving platter, and let sit at room temperature for at least 20 minutes before cutting. (For a firm cake, serve after 20 minutes; for a softer mousse-like cake, let sit for another 15 minutes after cutting.)
To garnish, place sweetened whipped cream in a pastry bag fitted with an open-star tip*. Pipe 8 spirals evenly spaced around outside edge of cake and sprinkle with wafer crumbs, if desired.
Notes
*We used Nabisco Famous Chocolate Wafers and a Wilton 1M decorating tip.
Recipe by Victoria at https://victoriamag.com/creamy-pumpkin-icebox-cake-recipe/