For the chocolate shock cake, melt butter with water in a saucepan. Stir in sugar and vanilla sugar and heat until sugar is dissolved. Add cocoa and stir well.
Remove saucepan from heat and let cool slightly. Stir in the eggs and mix well. Stir in flour and baking powder with a whisk.
Pour the very liquid mixture into the greased cake pan and bake for about 60 minutes at 175 degrees.