Place the chocolate in a heatproof bowl, microwave for 50 to 60 secs & whisk.

In a separate bowl, mix cocoa powder and water. Keep that aside.
Whip the cream until thickened.

Mix cocoa paste and chocolate, add that into the whipped cream.
Mix and fold the cream.

Fill the glasses with chocolate mousses and whipped cream, chill in the fridge for at least 1 hour.
Top with extra whipped cream & serve.

Note: I used the ready whipped cream spray for filling the glass.