Chill your tools. Place a metal mixing bowl and beaters in the freezer for 10 minutes. Cold equipment helps the cream whip faster and hold its structure.

Whisk the dry mix. In a small bowl, whisk together 3 tablespoons cocoa powder, 3–5 tablespoons powdered sweetener (to taste), and a pinch of salt. Breaking up clumps now keeps your mousse silky.

Start the cream. Pour 1 cup cold heavy whipping cream into your chilled bowl. Beat on medium speed until it thickens slightly and soft peaks begin to form.

Add flavor. Sprinkle in the cocoa mixture and add 1 teaspoon vanilla extract. If using, add 1/4 teaspoon espresso powder for deeper chocolate flavor.

Whip to peaks. Beat on medium-high until the mousse reaches medium to stiff peaks. It should look fluffy and hold ridges, but still feel smooth—stop before it looks grainy.

Adjust sweetness and texture. Taste and add a little more powdered sweetener if needed. If it’s too thick, blend in 1–2 tablespoons more cream until velvety.

Optional chocolate boost. For extra richness, fold in 1–2 tablespoons finely grated very dark chocolate or melted and cooled 90% chocolate. Fold gently to keep volume.

Chill or serve. Spoon into cups. Serve right away for a soft mousse, or chill 30–60 minutes for a firmer set.

Finish with toppings. Add a dollop of whipped cream, a few shaved chocolate curls, or crushed toasted nuts for contrast.