Make the crust: In a medium bowl, whisk together the flour and sugar. Add the cold butter and use a pastry blender or your fingers to work it into the flour mixture until it resembles coarse crumbs. Gradually add the ice water, stirring with a fork until the dough comes together in a ball. Wrap the dough in plastic wrap and refrigerate for at least 30 minutes.
Roll out the crust: On a lightly floured surface, roll out the chilled dough to a thickness of about 1/8 inch. Transfer the dough to a 9-inch tart pan with a removable bottom. Trim the edges of the crust to fit the pan.
Chill the crust: Refrigerate the crust for at least 30 minutes.
Make the filling: In a large bowl, whisk together the egg yolks, sugar, lemon juice, and melted butter until well combined.
Add the lemon zest and vanilla: Stir in the grated lemon zest and vanilla extract.
Add the heavy cream: Add the filling:** Add the heavy cream and whisk until stiff peaks:** Add the filling:** Add the lemon juice:** Add the lemon juice:** Add the cream:** Add the lemon juice and lemon zest:** Add the lemon juice and lemon zest to the cream and whisk until stiff peaks form.
Assemble the pie: Pour the filling into the chilled crust and smooth the top with a spatula.
Bake the pie: Bake the pie in a preheated oven at 375°F (190°C) for 40-45 minutes, or until the filling is set and the crust is golden brown
Make the whipped cream: In a medium bowl, whip the heavy cream and granulated sugar until stiff peaks form.
Top the pie: Top the pie with the whipped cream and a sprinkle of lemon zest, if desired.