To make the mug cake, add the wet ingredients (buttermilk, vegetable oil and 2-5 drops of red food colouring) into a mug. I only needed 2 drops of Americolor super red food colouring.

Add the sugar, salt and cocoa powder and whisk with a fork until smooth. Fold in the flour and heat on full power in the microwave for between 1 minute to 1 minute 30 seconds, depending on the power of your microwave. Check at 1 minute, and 1 minute 15 seconds. The cake should be moist so if testing with a toothpick, some crumbs should cling.

Remove from the microwave and allow to cool fully before frosting. You can speed this up by popping in the fridge for around 30 minutes - 1 hour, or pop in the freezer for 15 minutes if you're impatient like me.

Once fully cooled and to make the cream cheese frosting, add the butter and cream cheese to a clean mug and beat with a clean fork until softened further. Gradually add in the icing sugar, beating after each addition. You may not need to add in the milk, so only add if needed.

Spoon or pipe the frosting over the cooled cake and add a dash or so of sprinkles if desired.

This cake is best enjoyed immediately or on the same day - cover with plastic wrap and pop in the fridge for later.