This Pumpkin Spice Trifle is super easy, make-ahead, and show-stopping. Everyone will love the pretty look of this tasty trifle. Most importantly, it is full of deliciousness in every bite! Note: Chill a bowl and the whisk beaters of an electric mixer beforehand.
In a chilled bowl, add heavy whipping cream, powdered sugar, and vanilla. Using chilled beaters of an electric mixer, beat until soft peaks almost form. Microwave gelatin/water mixture for 5 seconds or until it is a thick liquid, but not hot. It should be lukewarm. In a slow stream, gently pour in the liquid gelatin straight into the whisks while you continue to beat. Be sure to fully incorporate the gelatin mixture into the whipped cream. Beat until stiff peaks form. It's fine if you over-beat it. Set aside to chill.
In a bowl, stir together the prepared instant pudding, pumpkin pie filling, brown sugar, and cinnamon until well incorporated. Chill.
In a trifle bowl, crumble half of the baked spice cake into the bottom and press down to form an even layer. Add half of the pudding/pumpkin mixture on top. Add half of the broken gingersnaps. Add half of the stabilized whipped cream. Repeat layers.
If desired, sprinkle top with cinnamon for garnish. Cover loosely and place in fridge to chill overnight.