In a mixing bowl, combine the whipped topping, vanilla protein powder, vanilla extract, and pumpkin pie spice. Gently fold these ingredients together until well combined.

Incorporate the canned pumpkin puree into the mixture. Stir until the pumpkin is evenly distributed throughout the mousse.

Add the vanilla sugar-free pudding into the mixture. Gently fold it in until fully combined. Ensure there are no streaks of pudding visible.

Place the mousse in the refrigerator to chill for at least 1-2 hours. This helps to set the mousse and allows the flavors to meld.

If using crackers or cookies for layering, take serving glasses or a large dish and start by placing a layer of crushed or whole crackers/cookies at the bottom.

Spoon or pipe the chilled protein pumpkin mousse over the layer of crackers/cookies.

Repeat the layering process with alternating layers of mousse and crackers/cookies until you reach the top of the serving dish. Ensure the final layer is the mousse.

For a firmer texture and melding of flavors, refrigerate the assembled mousse for an additional 30 minutes to an hour before serving.