First up preheat your oven to 180°C/ 160°C/ Gas Mark 4. Grab your 2lb loaf tin and give it a quick grease and line with baking parchment.

Pop your margarine and sugar into a bowl and beat together until light and fluffy. 

Add the eggs and lime zest and continue to mix until your mixture is smooth, if it begins to curdle don’t worry add a spoonful of flour and it’ll be lovely and smooth in no time. 

Sieve over the remaining flour and fold through your mixture until just combined. Pour in your tonic and mix again.

Pour your mixture into your prepared loaf tin and smooth the top. Pop in the oven to bake for 45-50 minutes until your sponge has risen and is a lovely golden brown, to double check it’s fully baked pop a skewer into the centre and it should come out clean. 

Whilst your cake is baking lets get the syrup ready; pop the sugar, gin and tonic in a saucepan and gently heat over a low heat to melt to sugar. Set aside. 

Once your cake is out of the oven poke a few small hole in the top using a skewer and pour over your syrup and allow to soak in. 

Once your cake has cooled, pop the icing sugar, gin and lime juice in a bowl and mix together until your have a smooth, pourable consistency – if it’s too thick add a bit more liquid, if it’s too runny add a bit more icing sugar. Pour your icing over the top of your cake and use a spoon to help tease the icing to cover the top of the cake and drip down the sides. 

Finally decorate your cake with some lime slices and sprinkling of lime zest. Ta-dah you’ve just turned a drink into a scrumptious cake!