How to make
Mix the milk, butter, sugar, cocoa and vanilla over low heat to melt and homogenize. Then remove it from the heat and let it cool.
Beat the eggs in a bowl and add the flour and baking powder. Mix until you get a stiff mixture, then add the chocolate mixture and cool. Pour the resulting mixture into a greased tray.
Optionally add crushed walnuts. Bake in a 360°F (180 °C) preheated oven until ready.
Meanwhile, prepare the glaze. On a container on low heat, mix and heat the chocolate, butter, water and sugar. Stir to thicken. Remove from the heat and let it cool.
Cut the finished cake into diamond shapes and pour the glaze on with a spoon.