2/3 c. sugar
3 tbsp. cornstarch
1 c. milk
4 egg yolks
1 tsp. finely grated lemon peel
1/4 c. lemon juice
1/4 c. butter, softened
1 c. sour cream
1 (9-inch) pie shell, baked and cooled

Mix sugar and cornstarch in a microwave 8-cup measuring cup. Whisk in milk until smooth; add yolks until well blended. Stir in lemon peel and juice. Add butter. Heat in microwave until just before it boils, about 5 minutes. Remove and stir.

If needed, use an eggbeater until mixture is very smooth. Cover and place in refrigerator about 1 hour until cold. After mixture is cold, stir in sour cream until well blended. Pour into pie shell. Garnish with Cool Whip. Chill overnight.