01 - Combine flour, powdered sugar, and salt in a bowl. Add cold butter and rub in with fingertips or a pastry cutter until mixture resembles coarse crumbs. Add egg yolk and 2 tablespoons ice-cold water; mix until dough just comes together, adding extra water if needed. Flatten dough into a disc, wrap in plastic, and chill for 30 minutes.
02 - Heat oven to 350°F (175°C).
03 - Roll out chilled dough on a lightly floured surface to fit a 9-inch tart pan. Press dough into pan and trim any excess. Prick base with a fork.
04 - Line pastry with parchment paper and fill with baking beans. Bake for 15 minutes, then remove weights and paper and bake for an additional 10 minutes until golden. Let cool slightly.
05 - Whisk eggs and sugar until smooth. Add lemon zest, lemon juice, and heavy cream; whisk until fully combined.
06 - Pour filling into warm pastry shell. Bake for 20 to 25 minutes, or until filling is just set with a slight wobble in the center.
07 - Allow tart to cool to room temperature, then chill for at least 2 hours before serving.