Melt the chocolate with the butter and mix well. Carefully stir in the egg whites.
Beat the egg yolks with the sugar until spongy and then add to the mixture.
Sift the cocoa and the flour together and mix gently
Into your four 3 x 2 inch metal baking rings, pour 1/3 inch of the mixture to form a base.
Place the molds into the freezer for 20 min.
Add a generous teaspoonful of dulce de leche into the center of each base and then fill up the rings to the top with your mixture.
Cook at 320 degrees Fahrenheit for 15 min then lower the oven temp to 250 degrees Fahrenheit and bake for a further 15 min.
Remove from oven and leave to cool. Remove from the mold by passing the blade of a knife along the inside edge of the baking ring.
Serve cold with slices of fruit, ice cream or whipped cream.