To a bowl, pour the heavy cream. Add the cocoa powder, powdered sweetener, and espresso powder. Using a hand blender, beat the mixture at a low speed.
Step 2
Once the dry ingredients have dissolved, turn the speed up to medium-high. Keep beating until stiff peaks form. Set the bowl aside.
Step 3
Fit a piping bag into an empty cup. Transfer the mousse into the piping bag and cut its tip. Divide the mousse into 2 serving glasses.
Step 4
Sprinkle some espresso powder on top as garnish. Place the mousse glasses in the fridge for at least 20 minutes to set. Serve or store in the refrigerator for up to 3 days.