Directions

1. 1

   Remove puff pastry sheets from the freezer and allow them to thaw at room temperature according to package directions, about 30-40 minutes. While they defrost, peel, core, and dice the Granny Smith apples. Transfer diced apples to a bowl, pour lemon juice over them, and toss well to coat evenly. This prevents the apples from browning.

2. 2

   In a medium saucepan, melt 3 tablespoons of butter over medium heat. Continue heating, swirling occasionally but not stirring, until the butter turns a deep amber color with a nutty aroma, about 5-7 minutes. Add the lemon-coated apples, brown sugar, granulated sugar, and cinnamon. Stir frequently until the apples begin to soften, about 8-10 minutes.

3. 3

   In a small bowl, whisk cornstarch with cold water until smooth and fully dissolved. Pour the cornstarch slurry into the apple mixture while stirring constantly until the filling thickens, about 2-3 minutes. The mixture should coat a spoon.

4. 4

   Remove the pan from heat and transfer the apple filling to a clean bowl. Let cool to room temperature, stirring occasionally, about 15 minutes. Preheat your oven to 400°F (or follow your puff pastry package instructions).

5. 5

   Once the pastry sheets are thawed, carefully unwrap and lay them flat on a lightly floured work surface. Using a pizza cutter or sharp knife, cut each sheet into four equal squares, giving you eight squares total.

6. 6

   Place about 2 tablespoons of cooled apple filling in the center of each pastry square. Fold one corner of the square diagonally over to the opposite corner to form a triangle, then press the edges gently to seal. If desired, use a fork to crimp the edges for a decorative finish.

7. 7

   Transfer the turnovers to a parchment-lined baking sheet. Bake in the preheated oven for 15-18 minutes, until the pastry is puffed and golden brown on all sides.

8. 8

   Remove the baking sheet from the oven and transfer the turnovers to a wire cooling rack. Allow them to cool slightly, about 5 minutes.

9. 9

   While the turnovers cool, prepare the brown butter icing. In a clean saucepan, melt the remaining 2 tablespoons of butter over medium heat. Swirl the pan occasionally until the butter turns a dark amber color, about 3-4 minutes. Remove from heat and quickly add the milk, whisking constantly. Gradually whisk in the powdered sugar until smooth. Stir in the vanilla extract and salt.

10. 10

    Transfer the warm brown butter icing to a small piping bag or plastic bag with a small corner snipped off. Drizzle the icing decoratively over each cooled turnover.

11. 11

    Serve the turnovers warm or at room temperature. Store any leftovers in an airtight container at room temperature for up to 2 days.