FOR THE TARTS, COMBINE:
2 Tbsp. each granulated sugar and brown sugar
¼ tsp. each table salt and ground cinnamon
1 Granny Smith apple, thinly sliced
1 red Bartlett pear, thinly sliced
1 Tbsp. fresh lemon juice
1 sheet frozen puff pastry (½ pkg.; 8.65 oz.), thawed, halved horizontally
FOR THE CARAMEL, COMBINE:
¼ cup packed brown sugar
2 Tbsp. unsalted butter
2 Tbsp. heavy cream
¼ tsp. pure vanilla extract
⅛ tsp. table salt Finely chopped toasted pecans
1) Preheat oven to 425°. Line a baking sheet with parchment.
2) For the tarts, combine granulated sugar, brown sugar, salt, and cinnamon.
3) Toss apples and pears with lemon juice, then toss with sugar mixture.
4) Place puff pastry halves on prepared baking sheet. Alternate apple and pear slices, overlapping, onto pastry halves, leaving an edge around all sides. Slightly pinch edges around tarts to enclose (this helps the edges puff up around the outside). Bake tarts until golden brown, 20–25 minutes.
5) For the caramel, combine brown sugar, butter, cream, vanilla, and salt in a saucepan and heat over medium-low until thickened, 5–7 minutes. Drizzle tarts with caramel, then top with pecans.