In a mixing bowl, combine flour, lemon zest, lemon juice, milk, and egg yolks. Beat egg whites until stiff peaks form. Gently fold egg whites into mixture. Pour mixture into pastry-lined pie pan.
Bake lemon sponge pie at 450° F. for 10 minute. Reduce heat to 325° F.
25 to 35 minutes until cake tester poked in the center comes out clean.