Preheat your oven to 350°F (175°C).
In a mixing bowl, combine flour and powdered sugar.
Add chilled butter and mix until crumbly.
Incorporate the egg and mix until a dough forms.
Press the dough into a tart pan evenly across the bottom and up the sides.
Bake the crust for 15 minutes or until lightly golden.
In another bowl, whisk together granulated sugar and eggs.
Add lemon juice, zest, and heavy cream; mix well.
Pour the lemon filling into the baked crust.
Bake for another 15 minutes until set but slightly jiggly in the center.