Preheat the oven to 160 C / Gas 2/3. Grease and line a 450g loaf tin.
Beat the butter and sugar together until light and fluffy. Beat in the eggs, one at a time until well blended. Add the lemon juice, zest and curd. Fold in the flour and mix well. Transfer to the prepared loaf tin.
Bake in the preheated oven for 50 to 60 minutes until a skewer inserted into the centre comes out clean. Remove from the oven and while still hot, spread the lemon marmalade over the top of the cake and leave to cool for 1 hour. Slice and serve.