Preparation

• Preheat the oven to 375°F.
• If using a packaged pie crust, follow directions to pre-bake. For homemade, line crust with foil, fill with weights, bake for 20 minutes, remove weights and foil, poke holes, bake for 15 more minutes.
• Make the lemon filling: Whisk egg yolks, then in a saucepan, combine cornstarch, sugar, salt, and water. Bring to boil while whisking, let simmer until thick.
• Temper yolks with cornstarch mixture, add back to pot, bring to boil, cook for 3-4 minutes, and stir in lemon juice, zest, and butter.
• Lower oven to 325°F.
• Prepare meringue mixture: Whisk together cornstarch and water, heat until thickened, set aside.
• Whisk sugar and cream of tartar, set aside. Beat egg whites and vanilla, gradually add sugar mixture until soft peaks form, then add cornstarch mixture until stiff peaks.
• Heat lemon filling until bubbling hot, pour into pre-baked pie shell.
• Spread meringue over filling, ensuring no gaps between meringue and crust, create peaks with spoon.
• Bake for 20 minutes at 325°F until meringue is golden, then cool completely to room temperature before serving.