01 - Set oven to 350°F and allow to fully preheat.
02 - Combine flour, powdered sugar, and salt in a food processor. Add cold cubed butter and pulse until mixture forms coarse crumbs. Incorporate egg yolk and 2 tablespoons cold water, pulsing just until dough begins to clump, adding additional water only if needed.
03 - Transfer dough to a lightly floured surface. Shape into a disk, wrap in plastic, and chill for 30 minutes.
04 - Roll chilled dough to 1/8-inch thickness. Fit into a 9-inch tart pan, trimming excess and pricking the base with a fork. Freeze for 10 minutes.
05 - Line crust with parchment and fill with pie weights or dried beans. Bake 15 minutes, remove weights, then bake 8 to 10 minutes more until golden. Let cool briefly.
06 - Reduce oven temperature to 300°F.
07 - Whisk heavy cream, granulated sugar, eggs, egg yolks, lemon zest, lemon juice, and a pinch of salt until smooth.
08 - Carefully pour lemon filling into the cooled tart shell. Bake for 20 to 25 minutes until edges are set and center is just slightly wobbly.
09 - Allow tart to cool completely on a wire rack, then refrigerate at least 1 hour before serving.
10 - Dust with powdered sugar and finish with fresh berries or candied lemon slices as desired.