01 - Set oven to 350°F (175°C) to prepare for baking the crust.
02 - In a food processor, combine flour, powdered sugar, and salt. Add cold, cubed butter and pulse until the mixture resembles coarse crumbs.
03 - Add the egg yolk and 2 tablespoons cold water. Pulse just until the dough begins to form. Add additional water, one teaspoon at a time, if needed.
04 - Transfer dough to a lightly floured surface, shape into a disk, wrap in plastic, and chill for 30 minutes.
05 - Roll dough to 1/8-inch thickness. Press it evenly into a 9-inch tart pan. Trim excess edges, prick the base with a fork, and freeze for 10 minutes.
06 - Line crust with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes, remove weights, and bake an additional 8 to 10 minutes until golden. Cool slightly.
07 - Reduce oven heat to 300°F (150°C) to bake the filling.
08 - In a mixing bowl, whisk together heavy cream, granulated sugar, eggs, egg yolks, lemon zest, lemon juice, and a pinch of salt until smooth.
09 - Pour the lemon filling into the slightly cooled tart shell. Bake for 20 to 25 minutes until the edges are set and the center remains slightly jiggly.
10 - Cool the tart completely on a wire rack, then refrigerate at least 1 hour until well chilled.
11 - Before serving, dust with powdered sugar and garnish with fresh berries or candied lemon slices as desired.