Sift together flour, cocoa powder and baking powder. Set aside.
In a large mixing bowl, beat eggs, sugar, cake stabiliser (ovalette), water, sifted ingredients with high speed until fluffy.
Add in the oil and mix slowly until the oil is blend well. Add in 1 tsp chocolate emulco and mix again until well combined.
Pour the mixture into 10 x 10inch baking pan, which have been greased and lined with greaseproof paper. Bake in 180 degrees C preheated oven for 45 minutes until done. Let cake cool in pan for a few minutes before turning out to wire rack. to cool down completely.
For the topping:
Break the chocolate bar into chunks and in butter and melt. Set aside.
When the cake is ready, spread the melted chocolate on top and sprinkle with chocolate rice.