Combine sugar and cornstarch in saucepan. Add milk, egg yolks, butter and lemon peel. Cook, stirring over medium heat until thickened. Continue cooking about 1 minute more. Remove from heat and stir in lemon juice. Refrigerate until cool. Stir in sour cream. Pour into pastry shell. Cover and chill at least 4 hours. Garnish with raspberries just before serving.

Recipe Courtesy of The California Egg Commission.