In a small bowl , mix together the milk and vinegar. Keep aside.
In another bowl , mix together the egg, oil , vanilla and food colouring.
In a small bowl , mix together with a fork the flour , cocoa, sugar , salt and baking powder.
Add both liquid mixtures to the flour mixture and mix until smooth.
Divide into the two mugs or microwaveable bowls. Make sure the mugs / bowls are only half full .
Microwave , one at a time , at full power for 1 1/2 minutes for mug , 1 minute for a bowl. The cakes are done when they spring to the touch. If not done , Microwave again for 10 second intervals checking each time. Let cool for about three minutes.
If you are decorating with icing sugar , as they are cooling , prepare your stencil. Cut a piece of parchment or wax paper the size of your mug / bowl . Draw a heart shape in the centre and cut it out .Place the stencil over cake and sprinkle icing sugar over the cakelets.