Pre-heat the oven to 180C/160C fan/gas 4. Grease and line a loaf cake tin.

Put the butter and sugar in a bowl and mix until light and fluffy - a hand mixer will make light work of this. Gradually add in the beaten egg, then stir in the lemon zest. 

Sift in the flour and baking powder and mix until combined. Finally add the milk and mix until smooth. Turn out into the lined tin and bake in the oven for 35 mins. Poke in the centre with a cocktail stick to check if it's cooked - if the stick comes out clean it's done. If not give it five more minutes and check again.

To make the drizzle combine the gin, sugar, dried rosemary and lemon juice in a bowl and mix until combined.

Take the cake out of the tin but leave it in the greaseproof paper. Sit it on a cooking rack with a dish underneath it. Poke holes all over the surface of the cake, then spoon the gin drizzle all over the top, gradually letting it soak into the holes and down the sides. Leave the whole thing to cool and the drizzle will form into a pleasing crust.

Once cooled, transfer onto a cake plate, slice and serve with a generous Gin & Tonic - cheers!