How to Make It
In a small bowl, whisk the cream with the egg yolk. In a large bowl, combine the 1 1/4 cups plus 2 tablespoons of flour with the sugar and salt. Using a pastry blender or 2 knives, cut the butter into the dry ingredients until the mixture resembles coarse meal. Using a rubber spatula, gently stir in the yolk mixture. Using your hands, gently knead the pastry just until it comes together. Wrap in plastic, flatten it into a disk and refrigerate for at least 1 hour.
Preheat the oven to 375° and coat a 9-inch fluted tart pan with a removable bottom with vegetable oil spray. On a floured work surface, roll out the pastry to a 12-inch round and ease it into the pan, pressing it into the corners. Roll the rolling pin over the tart pan to cut off any excess pastry. Refrigerate for 10 minutes.
Line the tart shell with parchment paper and fill it with pie weights or dried beans. Bake in the center of the oven for 15 minutes. Carefully remove the paper and weights and bake the tart shell for 20 minutes longer, until golden brown. Let cool completely.
In a large, heavy saucepan, combine the whole eggs, egg yolks, sugar, lemon juice and salt and whisk until smooth. Set a strainer over a bowl near the stove. Cook the custard over moderate heat, whisking constantly, until thickened enough to coat the back of a spoon, about 3 minutes. Remove from the heat and add the butter a few pieces at a time, gently whisking until incorporated. Immediately strain the filling into the bowl. Scrape the filling into the cooled tart shell and refrigerate until chilled, about 2 hours.
Remove the tart ring and cut the tart into wedges. Serve with whipped cream.