Ensure that all ingredients are at room temperature.
Butter and flour a 9" round baking tin or a loaf tin + 2-3 other smaller tins.
Preheat the oven at 180xb0C.
Over a large paper, sieve the flour, baking soda, baking powder, cocoa powder, instant coffee and salt until combined and airy.
In a large bowl, combined the melted butter and sugar by mixing together with a spatula. Whisk in the yogurt well. To this, add the flour in 3 batches, mixing well after each addition along with some of the milk to aid in mixing.
At the end of this all the flour and milk should be incorporated into the batter.
Add vanilla extract and 1 tsp vinegar and give it a final mix with the spatula. Using the spatula scrape out the batter into the loaf tin plus two other smaller tins.
The loaf will bake for 35-40 mins (until tester comes out clean) - reduce baking time for smaller cakes.
Remove on a cooling rack and after 5-10 minutes, unmould cakes and let them cool further before slicing or decorating.