Add the cream cheese to a stand mixer. Mix on high until smooth (about 2 minutes)
Add all of the remaining ingredients
Mix until stiff peaks form, about 2 minutes on high
Notes
Soften the cream cheese: Let it sit at room temperature for about 30 minutes, or microwave it for 5 seconds at a time until soft but not warm or melted.
Keep the heavy cream cold: This helps the mousse whip properly and hold its shape.
Use powdered sweetener: Granulated sweetener may leave the mousse gritty.
Storage: Refrigerate in an airtight container and serve cold.