1. Preheat the oven to 350 degrees. Grease the pan and grease it with flour or use butter paper. In a large bowl, mix the self-elevating flour with the granulated sugar. Sit aside.
2. In a saucepan, mix 1 cup of butter, 1 cup of coffee and 1/3 cup of cocoa. Bring to a boil with continuous stirring. Pour in ready dry ingredients. Using a hand mixer, mix the ingredients on medium speed until the moist and dry ingredients are completely mixed. Add the eggs and half a glass of milk. Mix medium speed for another minute or so, until well mixed.
3. Pour into a baking tray and bake for 25-30 minutes. When the cake is baked, a toothpick or fork should come out in the middle of the cake clean.
4. Equip the decorations. In a medium-sized saucepan, mix 1/4 cup butter, 4 tbsp yogurt, and 3 tbsp unsweetened cocoa powder. Bring to a boil over medium heat, and stir constantly.