Step 1

Add the butter to a mug and melt in the microwave for around 10-20 seconds.

Step 2

Add the honey, egg and vanilla and beat with a fork until combined.

Step 3

Add the sugar, flour and salt and beat again until fully combined and smooth.

Step 4

Cook in the microwave for around 1 minute 15 seconds to 1 minute 30 seconds (depending on your microwave power), then allow to cool to room temperature.

Step 5

Meanwhile, to make the frosting, add the butter and icing (confectioners') sugar to another mug and use a fork to cut the butter into the icing sugar until it reaches a clumpy texture, then beat with the fork until fluffy, around 1-2 minutes).

Step 6

Spoon the frosting into a small piping bag or a ziplock bag fitted with an open star or plain round tip and pipe a swirl onto the top of the cooled cake.

Step 7

(Optional) Drizzle with extra honey and serve immediately.