01 -
In a medium saucepan, whisk together granulated sugar, cornstarch, and salt until well combined. Gradually add water, stirring until smooth.
02 -
Set saucepan over medium heat and cook, stirring constantly, until mixture thickens and begins to boil. Continue boiling for 1 minute, stirring throughout. Remove from heat.
03 -
Stir a small amount of the hot mixture into the beaten egg yolks to temper, then return egg mixture to the saucepan, stirring constantly to prevent curdling.
04 -
Return saucepan to medium heat and bring to a gentle boil. Cook for an additional 2 minutes, stirring constantly. Remove from heat and stir in unsalted butter, fresh lemon juice, and lemon zest until smooth.
05 -
Pour hot lemon filling into pre-baked pie crust, smoothing the top. Allow to cool to room temperature, then refrigerate for at least 2 hours, or until completely set.
06 -
In a mixing bowl, whip heavy cream, powdered sugar, and vanilla extract until soft peaks form.
07 -
Spread whipped cream evenly over the chilled lemon pie just before serving.