Preheat your oven to 180oC (fan).
Line your cupcake tray with cupcake cases.
Crack all the eggs into a separate bowl & beat together until just starting to froth up, like the picture. > Takes 5 seconds. You can use the electric whisk for this too. In a large bowl, whisk together the butter & both types of sugar until fully combined>You’re looking for the mix to be paler, smooth & creamy! I use an electric whisk for 1 mins. Add 1.5 tbsp of cocoa powder and 2.5 tbsp coffee to a mug. Add 50ml of boiling water to the mug and mix together until smooth. >I think the boiling water helps to bring the coffee flavour alive in the cake so I wouldn't miss this step! Add the contents of the mug to the butter/sugar mixing bowl and whisk together until smooth.
Add the flour and eggs to the butter/sugar. Whisk together until JUST combined (10 seconds). >Don’t over whisk, otherwise you’ll lose the air bubbles & your cake won’t be quite so fluffy! Scrape right around the sides of the bowl and to the bottom, to pick up any excess flour and check there’s no bits of cake mix without the cocoa powder on the bottom of the bowl. Give the mixture one final everything is fully combined. >Still try not to over whisk! 3 seconds at most.>Make sure you scrape right down to the bottom of the bowl and around the sides so everything is thoroughly mixed. Place 1 heaped tbsp of the cake mix into each cupcake case. >I find its best to do this using two spoons –one to scoop up the mix and the other to scrape it into the cupcake case. >Each case should be about 2/3rd full. >GENTLY level each of them out slightly, so the cake mix is spread around the case quite evenly. Try not to get too much around the top 1/3 of the case (this is just to make your end result look extra neat!) Bake for approx 17 mins.>You’re looking for them to be firm on top but slightly springy to touch and a knife/skewer poked into the middle of the cake should come out relatively clean! Transfer to a baking tray and leave to cool thoroughly before moving onto the next step.