Collect together your equipment (see Recipe Notes below) and ingredients.

Preheat oven to Fan Oven 160°C/180°C/350°F/Gas 4

First make the sponge cake: simply put the flour, baking powder, salt and sugar in a mixing bowl and stir to combine.

Add the water and oil.

Whisk with an electric whisk until thoroughly combined.

Use a fine grater to zest both of the lemons – I do this directly over the mixing bowl.

Fold in the lemon zest.

Spoon into either a lined 900g/2lb loaf tin or a lined 20cm/8in square cake tin. Bake on the centre shelf of your oven for:

- loaf tin: 45 – 55 minutes or until cooked. Check the cake after 30 minutes. If it is browning too quickly, loosely cover with foil.

- square cake tin: 30 - 35 minutes or until cooked.

The cake is cooked when:

- the centre feels springy when lightly touched with your finger and no imprint remains, OR

- a toothpick or skewer inserted into the centre of the cake comes out clean.

Whilst the cake is baking, make the soaking syrup: heat the water and caster sugar in a saucepan over a moderately low heat until the sugar has dissolved.

Take off the heat and then add the lemon juice.

Drizzle the hot, cooked cake with the syrup: as soon as the cake comes out of the oven, puncture it all over with a cake tester or skewer.

Spoon the syrup over the cake, trying to let the middle absorb it as well as the sides. I use a spoon and a brush to ensure an even coverage.

Leave it to cool in the tin.

Cover with icing: when the cake is cool, mix the lemon juice with the icing sugar.

Mix until there are no lumps – use a balloon whisk if necessary. It should be a thick pouring consistency. If it is too thick, add a little more lemon juice or water. If too runny, add a little extra sugar.

Remove the baking parchment from the cooled cake and place it on a rack over a baking tray – this is just to help with easy clean up as some of the icing will trickle off the cake.

Pour over the icing, ensuring it covers the top of the cake – you may need to spread it with a knife.

If serving in slices: leave the icing to set before cutting into 16 squares.