Lemon curd cubes

Method

1. Set the oven to 180ºC (360F / gas mark 4).
2. To make the cake, beat all the ingredients together until smooth, then spoon the mixture into the lined tin and level the surface.
3. Bake the cake in the centre of the oven for 40-50 mins or until it has risen and is a pale golden colour, and just springs back when lightly pressed.
4. Remove the cake from the oven and leave it to cool in the baking tin for 10-15 mins, then transfer it to a wire rack to cool completely.
5. In the meantime, make the topping. Spoon the lemon curd into the piping bag and cut off the end of the bag to make a small hole.
6. Tip the icing sugar into a bowl and stir in enough water to give it a soft consistency. Working quickly, spread the icing over the top of the cake, then pipe parallel lines of lemon curd widthways across the top of the cake, at about 2cm (3/4in) apart.
7. To get the slightly zig-zag design, drag the tip of a cocktail stick or the point of a knife across the lines lengthways across. Work quickly before the icing sets. Leave the icing to set before trimming away the edges of the cake and then cut it into 15 cubes.