Prepare the lemons by rinsing under cool water, slicing in half, and scooping out the flesh. Squeeze juice into a measuring bowl and set the halves aside.

Heat the cream with granulated sugar and lemon zest over medium-low heat for about 5 minutes until sugar is dissolved and fragrant.

Stir in lemon juice and vanilla extract, mixing well until fully combined, allowing mixture to thicken.

Cool for 10 minutes, then pour into lemon halves and refrigerate for at least 1-2 hours until set.

For optional brûlée topping, sprinkle sugar over lemon halves and caramelize with a kitchen torch until golden brown.