Soften the cream cheese: Let it sit at room temperature for 30 minutes. This prevents lumps and makes the mousse smooth.
Whip the cream: In a chilled bowl, beat heavy whipping cream to stiff peaks. Set aside.
Don’t overmix; stop when it holds its shape.
Mix the base: In another bowl, beat the softened cream cheese until fluffy. Add pumpkin puree, powdered sweetener, vanilla, pumpkin pie spice, cinnamon, and a pinch of salt.
Adjust sweetness and spice: Taste and tweak. Add a little more sweetener or spice if you like a bolder flavor.
Fold in the whipped cream: Gently fold the whipped cream into the pumpkin mixture in two or three additions.
Keep it light to preserve the mousse texture.
Chill: Spoon into serving cups and refrigerate for at least 1 to 2 hours. It thickens and the flavors meld.
Serve: Top with a dollop of extra whipped cream, a sprinkle of cinnamon, or crushed roasted pecans for crunch.