01 - Preheat oven to 350°F.
02 - In a food processor, pulse flour, powdered sugar, and salt. Add cubed butter and pulse until the mixture is crumbly.
03 - Add egg yolk and 2 tablespoons cold water; pulse just until dough begins to clump together, adding more water if needed.
04 - Transfer dough onto a lightly floured surface, shape into a disk, wrap in plastic wrap, and chill for 30 minutes.
05 - Roll dough to 1/8-inch thickness and fit into a 9-inch tart pan. Trim excess, prick the base with a fork, and freeze for 10 minutes.
06 - Line crust with parchment and fill with pie weights or dried beans. Bake for 15 minutes, remove weights, then bake 8–10 minutes more until golden. Allow to cool slightly.
07 - Reduce oven temperature to 300°F.
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 filling into the baked crust and bake for 20–25 minutes, until the edges are set and the center wobbles slightly.
10 - Allow tart to cool completely at room temperature, then refrigerate for at least 1 hour before serving.
11 - Dust with powdered sugar and garnish with fresh berries or candied lemon slices as desired.