1/4 cup butter
1 cup sugar
1 lemon (juice and rind)
1/2 tsp. pure lemon extract (optional)
2 tbsp. flour
1 cup milk
2 eggs, separated

Preheat oven to 350°F.

Beat together the butter and sugar until light and fluffy.

Add the grated rind, juice, and extract, if using. Whisk egg yolks well and add. Add the flour and milk. Finally, add stiffly beaten egg whites.

Pour into an unbaked pie shell and bake in preheated oven for 45 minutes.