1 baked 9-inch pie shell, cooled
1/2 cup granulated sugar
1 tbsp grated lemon rind, divided
1/4 cup fresh lemon juice
3 tbsp cornstarch
1/4 tsp salt
2 large eggs
1 1/2 cups milk
2/3 of a 3-oz cream cheese brick
2 tbsp butter, softened
1 1/2 cups frozen whipped topping, thawed
In a large bowl, combine sugar, 2 1/2 teaspoons of the lemon rind, lemon juice, cornstarch, salt, and eggs; stir well.
Combine the milk and cream cheese in a medium-size heavy saucepan over medium-high heat and cook until the mixture reaches 10 degrees or starts to get tiny bubbles around the edge -- do not allow to come to a true boil. Gradually add to the sugar mixture, whisking constantly. Return mixture to the saucepan and cook over medium heat for 10 minutes or until thickened and bubbly, stirring constantly. Remove from the heat and stir in the butter.
Place pan into a large bowl that is almost full of ice and let set for 10 minutes or until mixture reaches room temperature; stirring occasionally. Spoon mixture into the prepared crust and cover the surface with plastic wrap. Chill for 3 hours or until set. Remove the plastic wrap and spread the whipped topping evenly over the pie. Sprinkle the remaining lemon rind over the whipped topping.