Sift together the flour, baking powder, and salt.
Whisk together the milk and egg whites in a medium bowl.
Put the sugar and lemon zest in a mixer bowl or another large bowl
and rub them together with your fingers until the sugar is moist and fragrant.
Add the butter and with the paddle attachment, or with a hand mixer,
beat at medium speed for a full 3 minutes, until the butter and sugar
are very light.
Beat in the extract, then add one-third of
the flour mixture, still beating on medium speed.
Beat in half of the milk-egg mixture, then beat in half of the
remaining dry ingredients until incorporated. Add the rest of
the milk and eggs beating until the batter is homogeneous,
then add the last of the dry ingredients.
Finally, give the batter a good 2-minute beating to ensure that it is thoroughly mixed and well aerated.
Divide the batter between the two pans and smooth the tops with a
Bake for 35-45 minutes or until the cakes are well risen and
springy to the touch - It really depends on your oven and location. I take it out
when my toothpick comes out with a small amount of crumbs, not clean.
Let the cakes to cool for about 10 minutes, then run a knife around the sides of the
cakes, unfold them and peel off the paper liners. Cool to room temperature, right side
up (the cooled cake layers can be wrapped airtight and stored at room temperature
overnight or frozen for up to two months).