01 - Combine peanut butter and softened cream cheese in a large mixing bowl. Beat with electric mixer until completely smooth and creamy, approximately 2 minutes.
02 - Add powdered sugar to the peanut butter mixture. Mix on medium speed until fully incorporated and no lumps remain, about 1 minute.
03 - Gently fold thawed Cool Whip into the peanut butter mixture using a spatula. Incorporate just until combined and airy, being careful not to overmix or deflate the mixture.
04 - Spoon or pipe the mousse evenly into 6 serving glasses or bowls. Refrigerate for at least 1 hour to allow flavors to meld and texture to set.
05 - Before serving, top each portion with chopped roasted peanuts and chocolate shavings or mini chocolate chips if desired.