01 - Preheat oven to 350°F (175°C).
02 - Combine flour, powdered sugar, and salt in a food processor or mixing bowl.
03 - Add cold cubed unsalted butter and pulse or blend until mixture resembles coarse crumbs.
04 - Add egg yolk and 2 tablespoons cold water, mixing until dough begins to form; add additional water if needed.
05 - Turn dough onto a lightly floured surface, shape into a disk, wrap, and refrigerate for 30 minutes.
06 - Roll dough to 1/8-inch thickness and press into a 9-inch tart pan; trim excess and prick base with a fork. Freeze for 10 minutes.
07 - Line crust with parchment paper, fill with pie weights or dried beans, and bake for 15 minutes. Remove weights and bake another 8 to 10 minutes until golden. Allow to cool slightly.
08 - Reduce oven temperature to 300°F (150°C).
09 - Whisk together heavy cream, granulated sugar, eggs, egg yolks, finely grated lemon zest, fresh lemon juice, and a pinch of salt until smooth and fully blended.
10 - Pour the lemon filling into the prepared crust and bake for 20 to 25 minutes, until edges are set and center is just slightly jiggly.
11 - Allow tart to cool completely on a wire rack, then refrigerate for at least 1 hour before serving.
12 - Dust the surface with powdered sugar and garnish with fresh berries or candied lemon slices as desired.