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.

Make the soaking syrup and drizzle over cake: heat the water and caster sugar in a saucepan over a moderately low heat until the sugar has dissolved. Stir from time to time.

Take off the heat and add the lemon juice and Dubonnet. The syrup is now ready.

As soon as the cake comes out of the oven, puncture it all over with a cake tester or skewer.

Spoon or brush the syrup over the cake, trying to let the middle absorb it, as well as the sides.

Leave the cake to cool in the tin for 30 minutes and then transfer to a cooling rack.

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

Use a balloon whisk or spoon to mix well, until there are no lumps. It should be a pouring consistency. If it is too thick, add a little more Dubonnet. If it is too runny, add a little extra sugar.

Remove the baking parchment from the cooled cake and place it on a wire rack on a baking tray – this is just to help with easy clean up incase the icing trickles off the cake.

Pour the icing over the cake, ensuring it covers the top of the cake and let it trickle down the sides