Step 1: In a medium bowl, combine the pumpkin puree, 1 cup sifted powdered sugar, pumpkin pie spice, and 1 teaspoon vanilla extract. Whisk until smooth. This is your luscious pumpkin layer for the Pumpkin Toffee Crunch Trifle. Set aside.
Step 2: In a separate large bowl, using an electric mixer, beat the softened cream cheese with the granulated sugar and 1 teaspoon vanilla extract until light and fluffy. Slowly add the 1/2 cup cold heavy cream and continue to beat until the mixture is smooth and holds soft peaks. This forms the delightful cream cheese layer.
Step 3: In a very large, chilled bowl, combine the 3 cups cold heavy cream, 1/2 cup sifted powdered sugar, and 1 teaspoon vanilla extract. Beat with an electric mixer on high speed until stiff peaks form. Be careful not to overbeat, or it will turn grainy.
Step 4: Now for the assembly of your beautiful Pumpkin Toffee Crunch Trifle! In a large (3-4 quart) trifle bowl, spread about one-third of the pumpkin mixture evenly on the bottom. Arrange about half of the pound cake cubes over the pumpkin layer, gently pressing them down.
Step 5: Next, carefully spread half of the cream cheese mixture over the cake layer. Sprinkle about one-third of the toffee bits over the cream cheese.
Step 6: Spread about one-third of the whipped cream over the toffee bits, smoothing it out. Repeat the layers: remaining pumpkin mixture, remaining cake cubes, remaining cream cheese mixture, and another third of the toffee bits.
Step 7: Top with the remaining whipped cream, creating a beautiful domed top or decorative swirls. Sprinkle the remaining toffee bits over the top of the Pumpkin Toffee Crunch Trifle for garnish.
Step 8: Cover the trifle bowl with plastic wrap and refrigerate for at least 4 hours, or preferably overnight, to allow the flavors to meld and the cake to soften. When ready to serve your Pumpkin Toffee Crunch Trifle, you can drizzle with caramel sauce or dust with a little cinnamon if desired.