Step 1: Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Step 2: Roll out the pastry dough on a lightly floured surface into a 12-inch circle or rectangle, then transfer it to the prepared baking sheet.
Step 3: In a small bowl, whisk together the melted butter, vanilla extract, and cinnamon.
Step 4: Arrange the pear slices over the pastry, leaving a 1-inch border around the edges. You can overlap them slightly for a beautiful presentation.
Step 5: Brush the pears with the butter and cinnamon mixture, ensuring they are evenly coated.
Step 6: Sprinkle the dark brown sugar and a pinch of sea salt evenly over the pears.
Step 7: Fold the edges of the pastry slightly over the pears to create a rustic border. Brush the pastry border with an egg wash (egg beaten with 1 tablespoon water).
Step 8: Bake the tart for 35-40 minutes, or until the pastry is golden brown and the pears are tender and caramelized.
Step 9: Remove from the oven and let the tart cool for at least 10 minutes before slicing and serving.