Step 1: Prepare the Pumpkin Pudding. In a large bowl, whisk together the pumpkin puree, instant vanilla pudding mix, cold milk, pumpkin pie spice, cinnamon, nutmeg, and brown sugar until well combined and smooth. Let it sit for 5 minutes to thicken.
Step 2: Make the Caramel Whipped Cream. In a separate large, chilled bowl, using an electric mixer, beat the very cold heavy cream, 1/2 cup caramel sauce, powdered sugar, and vanilla extract on high speed until stiff peaks form. Be careful not to overbeat, as it can quickly turn to butter.
Step 3: Begin Assembling the Trifle. Take a large trifle bowl (3-4 quart capacity) or a clear glass bowl. Spread a thin layer of caramel whipped cream (about 1/4 of the total) at the bottom of the bowl.
Step 4: Add the First Cookie Layer. Sprinkle about one-third of the crushed gingersnap cookies evenly over the whipped cream. For best results, use a food processor for a coarser crumb or crush them in a bag with a rolling pin.
Step 5: Add the First Pumpkin Layer. Carefully spoon about half of the pumpkin pudding mixture over the gingersnaps, spreading it gently to cover the cookies completely.
Step 6: Repeat Layers. Add another layer of caramel whipped cream (about 1/4 of the total), followed by another third of the crushed gingersnaps. Then, top with the remaining pumpkin pudding, spreading it smoothly.
Step 7: Finish with Remaining Layers. Add the final third of the crushed gingersnaps. Finish by spreading the remaining caramel whipped cream generously over the top of the trifle.
Step 8: Chill and Garnish. Drizzle additional caramel sauce over the top and garnish with optional toffee bits, chopped pecans, or whole gingersnap cookies. Cover the trifle tightly and refrigerate for at least 4 hours, or preferably overnight, to allow the flavors to meld and the gingersnaps to soften slightly into a cake-like texture.
Step 9: Serve. Scoop into individual serving dishes and enjoy your spectacular pumpkin gingersnap trifle caramel whipped cream recipe!