In a mixing bowl, combine the flour, water, and a pinch of salt. Knead the dough until it becomes smooth and elastic, then divide it into six equal portions.
Roll out each portion of dough into a thin rectangle, then brush it with melted butter.
Roll up the rectangle tightly, creating a log. Repeat this process with all six portions of dough.
Place the logs on a baking sheet and chill in the refrigerator for 30 minutes.
In the meantime, prepare the ricotta filling. Mix the ricotta, powdered sugar, egg yolk, vanilla extract, and lemon zest until smooth.
Preheat your oven to 375°F (190°C).
Take the chilled logs out of the refrigerator and cut them in half horizontally.
Roll out each piece into a thin, almost transparent sheet. You should be able to see your hand through it.
Spoon the ricotta filling into a piping bag with a star tip.
Pipe the filling onto each rolled-out dough sheet and fold them in half.
Bake for about 30 minutes or until the lobster tail pastries are golden brown and crisp.