Chop the chocolate and melt it in the microwave in 30-second intervals, or in a double boiler.
Put the chocolate in a mixer along with the dulce de leche, whip them together until combined. Set aside.
Whip 200ml of chilled whipped cream, transfer to a bowl and gradually add the mixture we've set aside, save just a bit of mixture for the next step.
Brush the glass dish in which the dessert will be assembled with the rest of the chocolate mixture you've just set aside.
Pour the cream into the glass dish and leave in the fridge for 2 to 3 hours.
Whip the rest of the whipped cream and pour it over the dessert, spread well.
Garnish with chocolate covered wafer biscuits, to taste.