Preheat the oven at 200 degrees Celsius.
Start with the cake, by melting the butter in a casserole.
In a bowl mix together the eggs and the sugar until it becomes white in color. Use an electrical mixer.
Add the vanilla sugar, cacao powder and salt in the sugar and egg mixture.
Add the flour and the melted butter and stir together with a wooden spoon.
Place a baking paper in an oven form approximately 25×35 cm.
Pour the batter on the paper in the oven form.
Place in the middle of the oven for 15 minutes.
In the mean while make the topping.
In a casserole add the sugar, syrup, butter, coconut flakes and the heavy cream.
Put middle heat, stir and when it's boiling, lower the heat and let it cook for 5 minutes.
Take out the cake when ready and pour evenly the glaze over it.
Place the cake in the lower part of the oven for 10 minutes.
Take out the cake and let it cool down.