In a medium bowl, beat the cream cheese, sour cream, and butter with an electric mixer until smooth.

Blend in the vanilla extract, sweetener, cocoa powder, and coffee powder until well incorporated. Set aside.

In a separate bowl, beat the heavy whipping cream until soft peaks form. (Be sure beaters are clean and dry.)

Add the sweetener and vanilla extract and beat until stiff peaks form.

Gently fold one-third of the whipped cream mixture into the cream cheese mixture to lighten it. Take care not to deflate the bubbles. Fold in the remaining two-thirds 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).