In small bowl, beat egg yolks with whisk. Set aside
*Tip: chill bowl and beaters in the refrigerator until you are ready to make the meringue.
In 2-quart saucepan, mix sugar and cornstarch;
gradually stir in water.
Cook over medium heat, stirring constantly, until mixture thickens and boils. Boil and stir 1 minute.
Immediately stir at least half of hot mixture into egg yolks;
stir back into hot mixture in saucepan.
Boil and stir 2 minutes; remove from heat.
Stir in butter, lemon peel, lemon juice.
Pour into pie crust.
Set the pie aside on the counter to cool.
In medium bowl, beat egg whites with electric mixer on high speed until foamy.
Beat in sugar, a little at a time; continue beating until stiff and glossy.
Peaks will form when ready.
Beat in vanilla.
Spoon onto pie filling.
Spread over filling, carefully sealing meringue to edge of crust.
Bake 8 to 12 minutes at 350F/180C or until meringue is light brown.
Cool, then serve or cover in a pie box and put in the refrigerator