Mix butter, graham cracker crumbs, and sugar together until well combined. Press crust into a 9" pie dish. Set aside.
Add 2 1/2 cups strawberries to a medium sized bowl. Sprinkle sugar over the strawberries, and allow the mixture to macerate for 15 minutes.
While the strawberries are macerating, spread lemon curd in an even layer on the bottom of the crust. Add remaining 2 1/2 cups of strawberries over the lemon curd, spreading them out in an even layer (as much as possible). Set aside.
With a fork, mash the macerated strawberries until the strawberries are in soft, small chunks.
Add macerated strawberries (including all liquid) and vanilla extract to a small saucepan and cook over med-low heat for 1-2 minutes, stirring occasionally.
Whisk cornstarch and water together to make a slurry, and add the mixture to the saucepan.
Cook the mixture for 4-5 minutes, or until the mixture has thickened.
Allow the mixture to cool completely (about 20-30 minutes).
Pour the strawberry mixture on top of the strawberries in the pie, spreading the mixture evenly.
Allow the pie to chill for at least 3-4 hours, or overnight.
Once the pie has chilled, whip heavy cream with a standing mixer or hand mixer until soft peaks form. Add in powdered sugar and vanilla extract and whip until combined.
Spread whipped cream over pie and top with strawberries, if desired.
Refrigerate leftovers.
Enjoy!