This recipe requires:
200g milk powder,
100g white chocolate for cooking,
100g dark chocolate for cooking,
Roast the hazelnuts over a low heat.
Heat the water to boiling and then add the margarine and sugar. Cook until the mixture is combined. When the mixture is combined, let it boil for another 10 minutes, then remove from the stove and leave to cool for 2-3 minutes. Lightly add powdered milk to the cooled mixture, stirring constantly.
When the powdered milk has melted and a fine, thick, uniform mass has been obtained, pour half the mass into a bowl with white and half the mass into a bowl with dark chocolate. Combine the chocolate with the milk powder mixture by mixing. When the masses are uniform they are ready to be poured into a mold. Pour the mixture with white chocolate on the bottom of the mold, which is previously covered with a transparent adhesive foil, and then arrange the roasted hazelnuts. Pour the remaining mixture of white chocolate over the hazelnuts, and the mixture of dark chocolate over it.
Flatten the cake nicely and leave it in the fridge for 2-3 hours to cool well. When the cake has cooled, take it out of the mold on a tray, cut it into pieces and serve.