Prepare and bake a 9″ single pie crust according to recipe directions, let cool

Whisk together sugar, milk, egg yolks, lemon juice, corn starch and lemon peel in a medium saucepan

Heat over medium heat, stirring until mixture becomes thick, remove from heat

Stir in butter

Cool at room temperature and when cool, add sour cream

Pour filling into baked pie crust and refrigerate for at least four hours

Garnish with whipped cream before serving