Preheat the oven to 180°C/gas mark 4. Grease and line an 18cm loose-bottomed cake tin. In a bowl, cream together the spread and sugar until light and fluffy. Beat in the eggs, then gently fold in the remaining cake ingredients until well combined.
Bake for 55 minutes to 1 hour until risen and golden (cover with foil for the last 10 minutes of cooking if the cake is too brown). Remove from the oven and leave to cool in the tin for 15 minutes.
Meanwhile, put the lemon juice and sugar into a saucepan and gently simmer until the sugar has melted. Boil for a few minutes until it has reduced a little and is thick and syrupy. Leave the syrup to cool.
Remove the cake from the tin and spoon over the syrup while the cake is warm. Let the syrup soak in, then sprinkle with the extra sugar. Decorate with the lemon zest to serve.