Step 1: Make the Pumpkin Cream: In a large bowl, combine pumpkin puree, softened cream cheese, 1 cup powdered sugar, cinnamon, nutmeg, ginger, and cloves. Beat with an electric mixer until smooth and lump-free. Taste and adjust spices if desired.
Step 2: Prepare the Whipped Cream: In a separate large, chilled bowl, whip cold heavy cream, 1/2 cup powdered sugar, and vanilla extract with an electric mixer until stiff peaks form. Be careful not to over-whip. Keeping your bowl and beaters cold helps.
Step 3: Assemble the First Layer: Arrange about one-third of the pound cake cubes in an even layer at the bottom of a large, clear trifle bowl (3-4 quarts).
Step 4: Add Pumpkin Cream: Spoon approximately half of the pumpkin cream mixture over the cake layer, spreading it evenly.
Step 5: Sprinkle Toffee: Sprinkle a generous layer of Heath bar toffee bits over the pumpkin cream.
Step 6: Layer Whipped Cream: Carefully spoon about one-third of the whipped cream over the toffee bits, spreading gently.
Step 7: Repeat Layers: Continue layering with another third of the pound cake, the remaining pumpkin cream, more toffee bits, and another third of the whipped cream.
Step 8: Final Layers and Chill: Finish with the remaining pound cake, a final scattering of toffee bits, and the last portion of whipped cream. Cover your assembled trifle tightly and refrigerate for at least 4 hours, or preferably overnight, to allow flavors to meld and cake to soften.
Step 9: Garnish and Serve: Garnish with a sprinkle of cinnamon or extra toffee bits just before serving.