Heat oven to 160C/140C fan/gas 3.
Line a muffin tin with 12 muffin cases.
With an electric whisk, whisk the butter,
250g of the sugar, eggs, flour, zest of
2 lemons and juice from 1 lemon until
just combined – don’t over-whisk. Fill the cases two thirds full, then bake on a middle shelf for
30 mins, until a skewer poked in comes
Cool for 10 mins, then transfer cakes to
a cooling rack on a tray and poke each a
few times with a skewer. Pour remaining
lemon juice over remaining 150g sugar
and zest 1 lemon, and immediately spoon
over the cakes. Leave to cool.