Preheat oven to 350°F.
Combine flour and half the sugar in a large bowl.
Cut cold butter into the flour mixture until it resembles coarse crumbs.
Press the dough evenly into a 9-inch tart pan.
Chill the tart shell in the refrigerator for 30 minutes.
Bake the shell for 20 minutes until lightly golden, then set aside.
Whisk eggs, the remaining sugar, lemon juice, lemon zest, and heavy cream in a heat-proof bowl.
Cook the mixture over low heat, whisking constantly, until thickened into a silky curd.
Pour the curd into the baked shell.
Bake for an additional 5 minutes to set the filling.
Refrigerate for at least 2 hours before serving.