Place cream cheese or mascarpone in a mixing bowl.
Add powdered sweetener and peanut butter.
Beat the mixture until smooth and creamy.
In a separate bowl, pour the cold heavy cream.
Whip the cream until soft peaks form.
Gently fold the whipped cream into the peanut butter mixture.
Add vanilla extract and a pinch of salt.
Fold everything together until smooth and fluffy.
Spoon the mousse into serving glasses.
Chill for about 20–30 minutes before serving if desired.
Top with whipped cream or crushed nuts if preferred.
