01 - Combine the peanut butter and softened cream cheese in a large mixing bowl. Beat with an electric mixer until completely smooth and creamy, scraping down the sides as needed.
02 - Add the powdered sugar to the peanut butter mixture. Mix on medium speed until fully incorporated and no lumps remain, about 1-2 minutes.
03 - Gently fold the thawed Cool Whip into the peanut butter mixture using a spatula. Mix with light, lifting motions just until combined and airy. Take care not to overmix or the mousse will lose its light texture.
04 - Divide the mousse evenly among 6 serving glasses, bowls, or ramekins. Use the spatula to smooth the tops if desired.
05 - Refrigerate the portions for at least 1 hour to allow the mousse to set and develop the proper creamy texture.
06 - Top each serving with chopped roasted peanuts and chocolate shavings or mini chocolate chips just before serving.