This apple tart recipe can be as homemade or as store-bought as your heart (and your schedule) desires. Your ingredient list is short and sweet, allowing the simple flavors of buttery pastry, tangy apples, sticky-sweet caramel and sea salt to shine.
Preheat the oven to 425 degrees F. Line a baking sheet with parchment paper or a silicone baking mat.
Slice the apples into thin pieces (about 1/4-inch). Put them in a large bowl, and then add the lemon juice, vanilla extract and brown sugar, tossing to thoroughly combine.
Unfold the sheet of puff pastry onto the lined baking sheet. Lightly score the dough by cutting a border 1 inch from the edges (do not cut through the pastry). Prick the pastry all over with a fork. Shake off any excess liquid from each apple slice, and then arrange them on the puff pastry inside the border area.
Whisk together the egg with 1 tablespoon water in a small bowl. Brush the edges of the pastry with the egg wash. Bake the tart until golden and puffed, 15 to 17 minutes.
Remove the tart from the oven, drizzle it with the caramel sauce and sprinkle it with sea salt if desired. Slice and serve immediately.