In a large mixing bowl, combine 1½ cups of heavy whipping cream and ⅓ cup of low-carb powdered sugar sweetener. Use an electric mixer on medium-low speed for about 1-2 minutes until the mixture begins to thicken and you see soft peaks forming.

Gradually sift in ⅓ cup of unsweetened cocoa powder into the whipped cream mixture. Using the mixer on low speed, carefully blend until fully incorporated.

Increase the mixer speed to medium-high and beat the mixture until stiff peaks form, being cautious not to overwhip.

Using a spatula, gently divide the finished mousse into four serving glasses or bowls, being careful to maintain its fluffiness.

Place the serving glasses in the refrigerator for about 10-15 minutes to allow the mousse to set slightly.

Once chilled, garnish with fresh berries, mint leaves, or additional cocoa powder for a lovely finishing touch.