Pre-heat your oven to Gas 4, 180°C, fan 160°C.
Sift the flour, sugar, salt and cocoa together into a large bowl and make a well in the centre.
In a small bowl, mix the bicarbonate of soda with 1 tbsp of the milk and pour into the well.
Add the rest of the milk, corn oil, golden syrup and vanilla essence and beat together to make a batter.
Pour the mixture into mini cupcake cases until about two thirds full. Bake for 15-20 minutes until a skewer inserted into the centre of a cake comes away clean.
Remove the cakes from the oven and allow them to cool whilst you make the butter icing.
To make the butter icing, sift the icing sugar into a bowl and add the softened butter, hot water and vanilla essence and beat well until smooth. This is easiest with an electric mixer.
Using a large star nozzle and when the cakes are cool, pipe the butter icing on to the cupcakes.
Make sure the cupcakes are cool before you add the butter icing, it will melt if you put it straight on.
These are best kept in the fridge.
Please note: this recipe has been created and uploaded by a member of the Tesco Real Food online community. Tesco does not test customer recipes so cannot accept responsibility for the content, validate the results or answer queries regarding them.