1: Put 150 g caster sugar into a mixer bowl. Grate the zest of 1 lemon and 1 lime into the bowl and mix well. Note: for maximum flavour, this mixture can be prepared the day before and left in the fridge overnight, covered with plastic film.
7: Finish by gently folding in the flour+baking powder+salt mixture a little at a time with a soft spatula.
8: Divide the cake batter between small tins or moulds about 5 x 2 x 2 inches (12 x 6 x 6 cm). Note: As always with cakes, if you want a nice opening on top when baking, try this very effective trick.
9: Bake for about 45 minutes.
10: Soak the cakes with 150 ml citrus syrup while they are still hot.
11: LEave to finish cooling on a wire rack.
Remarks
It is easier to leave the cakes in their tins or moulds while adding the syrup. This also allows the syrup to soak in more effectively.