In a bowl, whip heavy cream until stiff peaks form. Set aside.
In another bowl, mix cocoa powder, powdered sweetener, vanilla, and salt until smooth.
Gently fold whipped cream into the chocolate mixture until fully combined.
Optional: Add melted dark chocolate and fold in for a deeper fudge-like texture.
Spoon into small cups or bowls and chill in the fridge for at least 1 hour before serving.
Serve cold and enjoy your light, airy, and indulgent keto chocolate mousse!