Beat the egg whites, gradually add 1 cup sugar and 1/2 cup walnuts to them. Put baking foil in a baking dish, brush with oil and put some of the mixture on top. These products should be enough to bake 4 layers.
Put the water on the stove, add the remaining sugar and cocoa and wait until the water boils and starts to form a syrup. Stir continuously, and after removing from the heat, let it cool well.
In a deep container, mix the liquid chocolate with the butter and gradually add the egg yolks one at a time. While continuously whipping, gradually add the now cooled syrup.
On a large piece of foil, place the first layer, brush it well with the cream, then lay the second layer on top and repeat until you run out of products.
Brush the top with plenty of cream and cover the sides of the cake as well. Sprinkle the top with coconut or chocolate sprinkles. Leave it to rest for 2 hours at room temperature, then carefully wrap in foil and leave it in the refrigerator.