Zest and juice your lemons, placing both in a bowl large enough to hold your chopped apples. This will help prevent the apples from browning as you prepare them.
Peel, core, and chop your cooking apples into chunks. As you chop, immediately add them to the lemon juice bowl and stir well to coat. This keeps the apples fresh and vibrant.
Transfer the apples to a small pot with a lid. Add in the butter, sugar, vanilla, and salt. Stir everything together until well combined.
Cook the mixture over medium heat, covered, for 15 to 20 minutes. Stir occasionally to prevent sticking. You'll notice the apples releasing their juices, creating a sweet syrup.
Once the apples have softened, remove the lid and reduce the heat. Continue to cook until most of the liquid has evaporated, resulting in a thick, chunky applesauce. Feel free to mash some of the apples with a fork for texture, but leave some chunks intact.
Allow the filling to cool, then taste to see if it needs more sugar or a sprinkle of cinnamon for extra flavor.
Preheat your oven to 350° F and line a baking sheet with baking parchment to prevent sticking.
Create a template for your chaussons using paper. An elongated oval shape, approximately 4 by 5.5 inches, works best for a perfect turnover.
On a lightly floured surface, roll out your puff pastry. Use the template to cut out ovals with a sharp knife, ensuring you have enough for each pastry.
Brush the edges of each cut pastry with a little water. Place a generous spoonful of the cooled applesauce filling in the center of each oval.
Gently fold one side of the pastry over the filling and press the edges together to seal. Make sure they're well-sealed to prevent any filling from leaking out during baking.
Transfer the filled chaussons to your prepared baking sheet. Lightly score the tops with a sharp knife for design and to allow steam to escape.
Brush the tops with a little milk for a golden finish and bake in the preheated oven for 20 to 25 minutes, or until they’re golden brown and puffy.
Once baked, remove from the oven and let cool slightly before enjoying.
