Preheat oven on gas mark 4, line 12 hole cupcake tin with cases. Put your cocoa powder in a bowl and add in the boiling water then mix until incorporated.

Add all your ingredients to the cocoa powder mixture and mix until it is fully incorporated.

Using an ice cream scoop (1 scoop per case) add cake mixture to each case then put in the oven to cook for 20 minutes.

Once cooked, remove from the oven and let the cakes cool for a few minutes in the tin. After a few minutes, transfer the cakes to a cooling rack.

For the icing, beat the butter until smooth and light in colour. Add the icing sugar a bit at a time and beat until fully incorporated. Then add your salted caramel extract and the milk then beat until incorporated.

Fill a piping bag that has open star piping nozzle on and then pipe your swirls onto the cakes.