In a medium bowl, beat cream cheese, sour cream, and butter with an electric mixer until smooth.
Next, blend in the vanilla extract, sweetener, cocoa powder, and coffee powder until incorporated. Set aside.
In a separate bowl, beat whipping cream until soft peaks form.
Add sweetener and vanilla extract and beat until stiff peaks form.
Fold 1/3 of the whipped cream mixture into the cream cheese mixture to lighten it. Be sure to not deflate the bubbles. Fold in the remaining 2/3 of the mixture until the whipped cream is evenly incorporated.
Transfer the mousse into serving dishes and refrigerate until set before serving (about 2 1/2 hours).