Chill your tools. Pop your mixing bowl and beaters in the fridge or freezer for 10 minutes. Cold tools help the cream whip faster and hold its shape.

Combine dry ingredients. In a small bowl, whisk the cocoa powder and powdered sweetener to break up any clumps. This keeps the mousse ultra-smooth.

Start whipping the cream. Pour the cold heavy cream into the chilled bowl. Beat on medium speed until it looks slightly thick and foamy.

Add cocoa and sweetener. With the mixer running on low, slowly sprinkle in the cocoa-sweetener blend. Add vanilla and a pinch of salt if using.

Whip to soft peaks. Increase to medium-high and beat until soft peaks form—creamy and billowy, but not stiff. Stop and taste. Adjust sweetness or cocoa to your preference.

Finish at medium speed. Beat a few more seconds to reach medium peaks. Avoid overmixing. You want it silky and scoopable, not grainy or curdled.

Serve or chill. Spoon into small bowls or glasses. Eat right away for a soft mousse, or chill 30–60 minutes for a firmer, bakery-style texture.