Start by peeling, coring, and finely dicing four medium apples. I like to mix varieties like Granny Smith for tartness and Honeycrisp for sweetness. Place the diced apples in a bowl, and add the juice of one fresh lemon. This not only adds flavor but also prevents browning. Toss them around a bit to coat them evenly.

In a small saucepan over medium heat, melt the unsalted butter. Once melted, add the diced apples to the pan. Sprinkle in the dark brown sugar, ground cinnamon, sea salt, and nutmeg. Stir it all together and bring it to a light simmer. The sugar will melt, releasing its sweetness into the apples. Cook for about 5-7 minutes until they begin to soften.

To thicken your filling, stir in the cornstarch. The apples should now become syrupy, creating that desired sticky filling. Cook for an additional few minutes until you see bubbles forming. Remove the mixture from the heat and let it cool slightly. The filling should be thick but not overly mushy.

If you’re making your puff pastry, follow your recipe to create two batches. Roll out your pastry until about 1/8-inch thick. If you’re using store-bought, simply unroll it and ensure it’s at room temperature for better handling.

Using a round cutter, cut the dough into circles. Each circle should be large enough to hold a spoonful of filling while allowing for sealing the edges. Place a tablespoon of filling in the center of each circle.

Fold the pastry over the filling to create a half-moon shape. Use a fork to press around the edges, ensuring they are sealed well. This keeps the filling from spilling out during baking.

Preheat your oven to 400°F (200°C). Before baking, brush the tops of each pie with an egg wash made from beaten egg and water. Then, sprinkle a light layer of cinnamon sugar on top for added sweetness and color.

Place your assembled pies on a parchment-lined baking sheet. Bake them in your preheated oven for about 20-25 minutes or until they turn a beautiful golden brown. The aroma that fills your kitchen will be incredible!

Once baked, allow the pies to cool for a few minutes. This waiting period will help the filling settle, making them easier to handle. Serve warm, and prepare to enjoy!