Day 1: place the raisins in a bowl and spoon over the rum. Leave to soak overnight. Make the syrup: dissolve the sugar and water in a small saucepan over a low heat. Add lemon zest and boil for 5 minutes. Remove the pan from the heat and add the lemon juice, rum and grated nutmeg. Leave overnight.
Day 2: lightly grease the tin with butter and line it with greaseproof paper. Put the eggs