How to make
Beat the eggs well (they MUST be at room temperature) with the sugar, add the oil until absorbed by the mixture, then the yoghurt. Combine the flour, cocoa, baking powder and vanilla and sift them. Add the sifted mixture, while stirring, to the 1st mixture.
Pour it into a buttered oven dish and bake in a preheated 360°F (180 °C) oven for about 30-35 min.
Cut the baked cake into rhombuses and once cooled, pour the prepared warm glaze over it. To make the glaze, put the butter, cocoa, powdered sugar and water (can substitute with milk) in a water bath, stir until you get a nice, smooth chocolate mixture and pour it over the cooled brownie cake.