Put the milk in a large mug and stir in the vinegar. Leave for 15-20 minutes until you see it curdling.

Mix the coffee granules with the boiling water. Try to dissolve as much as possible, then set aside to cool.

In a large bowl, cream the sugar the butter. This will take some work, but the smoother and creamier you can get it, the better your cakes will be.

Add the flour, baking powder, bicarb, cocoa powder and salt to the bowl and start to gently mix it together. Add the coffee mixture and continue to gently mix until all the ingredients are just combined.

If making half chocolate peanut butter, half chocolate, remove half of the mix and add the peanut butter powder into one half - gently mix to incorporate.

With a large spoon, fill your cupcake cases to just below (0.5cm minimum) the top. If you're doing two flavours, try and remember which are which (we use purple & blue for peanut).

Bake at Gas Mark 5 (375f / 190c) for 30-40 minutes - check they are done using a clean skewer (insert into one cake and if it's clean, they are done)! Allow to cool before eating! Enjoy!