Preheat
the oven to 350°F/180°C/gas 4.
Butter a 9-inch (23-cm) spring form pan.
Plunge the pistachios into a saucepan of boiling
water for 30 seconds. Drain. Rub dry with a clean
kitchen towel, then carefully peel off the inner
skins.
Place the pistachios and sugar in a food processor
and chop finely.
Transfer to a large bowl and stir in the egg yolks,
lemon zest, cornstarch, baking powder, baking soda,
and salt.
Beat the egg whites in a medium bowl with an
electric mixer at high speed until stiff peaks form.
Use a large rubber spatula to fold them into the
batter. Spoon the batter into the prepared pan.
Bake for
25-35
minutes, or until a toothpick inserted into the
center comes out clean.
Cool the cake in the pan for 10 minutes. Loosen and
remove the pan sides and let the cake cool
completely on a rack.