How to make
Mix the flour, sugar, cocoa in a bowl. You can sift the flour if you like so there's no lumps.
Knead the products well with a spoon. To them add the yoghurt in which you've stirred the baking soda and softened butter.
Using a spoon or whisk again, mix all the ingredients well.
You need to obtain a smooth, homogeneous mixture, transfer it to a buttered and floured tray.
Bake in a preheated 360°F (180 °C) oven. It's ready when you stick a toothpick in it and it comes out dry.
Optionally, you can pour a mixture of melted chocolate and butter over it once baked.
