Add heavy whipping cream to a mixing bowl and whip with an electric mixer until soft peaks form. Set aside and avoid overbeating to keep the cream light and airy.

In a separate bowl, add softened cream cheese, powdered sweetener, and vanilla extract. Beat until the mixture becomes completely smooth and creamy. If making the chocolate version, mix in unsweetened cocoa powder at this stage.

Add the whipped cream to the cream cheese mixture and gently fold with a spatula. Keep folding slowly, stopping as soon as the mousse turns uniform, fluffy, and smooth. Avoid overmixing to prevent the mousse from becoming dense.

Spoon the mousse into serving cups or bowls. Refrigerate for at least 30 minutes to allow the mousse to firm up and develop its full creamy texture.

Garnish with fresh berries, a dusting of cocoa powder, or thin shavings of keto-friendly dark chocolate if you prefer an elegant finish. Serve chilled and enjoy.