If your eggs are in the fridge, take them out at least 20 minutes before you start.
Heat your oven to 200 Celsius and lightly butter 6 rammikins, then dust with cocoa powder and set aside (not the measured cocoa powder).
Break up the chocolate into small pieces (whacking it with a rolling pin does the trick) and place the chocolate and butter into a small pot on a low heat. Heat the mixture, stirring constantly until the chocolate has melted. Now take off the heat, add the vanilla essence and salt, stir well and set aside.
Separate the egg yolks and the whites putting 3 whites aside for use later.
Add the egg yolks to a large bowl and beat the yolks for about 30 seconds. Then add ½ the sugar(3 tablespoons) and cocoa powder and beat well until thick and glossy. Now add the chocolate mixture and mix with a metal spoon in a folding motion until blended and thick.
Now in a separate bowl add the 3 egg whites and beat on high until you reach stiff peak stage. (If you lifty the beaters out of the mixture the peak does not collapse), now add the remaining 3 tablespoons sugar and beat until smooth and glossy as if you were making meringues.
Add the egg whites to the chocolate mixture and fold in gently with a metal spoon. It must be evenly combined with a few white streaks. Spoon into the rammikins about ¾ full.
Place in the oven for 12 to 14 minutes or until the tops are cracked.
Serve immediately in or out of the rammikins. If you are removing them from the rammikins, allow them to cool for a few minutes then slide a sharp thin knife around the edges first. Serve with a little vanilla ice cream or fresh beaten cream.