1. Prepare the Gluten-Free Pastry Dough:

• In a large bowl, whisk together the gluten-free flour blend, salt, and optional granulated sugar.
• Add the cold, cubed butter to the flour mixture. Using a pastry blender, two knives, or your fingertips, quickly cut the butter into the flour until the mixture resembles coarse meal with some pea-sized pieces of butter remaining. Work quickly to keep the butter cold. Alternatively, pulse briefly in a food processor.
• Gradually add the ice water, 1-2 tablespoons at a time, mixing gently with a fork or your hands just until the dough starts to come together. Be careful not to add too much water – the dough should not be sticky. Gluten-free doughs often require slightly less water than traditional doughs, but can also seem dry initially; let it rest for a moment to hydrate.
• Turn the dough out onto a lightly floured surface (using your GF blend) and gently bring it together into a ball. Divide the dough in half, flatten each half into a disk, wrap tightly in plastic wrap, and refrigerate for at least 1 hour (or up to 2 days). Chilling is essential for gluten-free dough to hydrate the flours and make it easier to handle.

2. Prepare the Apples:

• While the dough chills, prepare the apples. Peel and core each apple, leaving them whole. You can use an apple corer or a small paring knife. Try to make the core opening wide enough to hold the filling but keep the base intact if possible (or slice a tiny bit off the bottom so they sit flat).

3. Prepare the Filling:

• In a small bowl, combine the softened butter, light brown sugar, ground cinnamon, ground nutmeg (if using), and pinch of salt. Mix well until it forms a paste.
• Divide the filling mixture evenly among the cored apples, packing it into the center cavity of each one.

4. Assemble the Dumplings:

• Preheat your oven to 375°F (190°C). Lightly grease a 9×13 inch baking dish or a similar large, oven-safe dish.
• Remove one disk of chilled dough from the refrigerator. Place it on a piece of parchment paper lightly dusted with gluten-free flour. Place another piece of parchment paper on top. Roll the dough out between the parchment paper sheets into a large circle or rectangle, about ⅛-inch thick. Gluten-free dough can be fragile, so the parchment paper helps prevent sticking and tearing.
• Remove the top piece of parchment paper. Cut the dough into 6 roughly equal squares (large enough to envelop an apple). You may need to gather and re-roll scraps (chill briefly if it becomes too soft). Repeat with the second disk of dough if needed to get 6 squares (dough yield can vary slightly).
• Place one filled apple in the center of each dough square.
• Moisten the edges of the dough square lightly with water using your fingertip. Bring the corners of the dough up and over the apple, pinching the seams together firmly to seal the apple inside. Trim any excess bulky dough at the top if necessary. Ensure it’s well-sealed to prevent the filling from leaking excessively.
• Carefully place each wrapped apple into the prepared baking dish, seam-side up if possible, leaving a little space between them.

5. Prepare the Cinnamon Syrup:

• In a medium saucepan, combine the water, granulated sugar, light brown sugar, butter, and ground cinnamon (or cinnamon stick).
• Bring the mixture to a boil over medium-high heat, stirring until the sugar dissolves and the butter melts.
• Reduce the heat and simmer gently for 3-5 minutes. Remove from heat. If using a cinnamon stick, remove it. Stir in the vanilla extract.

6. Bake the Dumplings:

• Carefully pour the prepared syrup around the dumplings in the baking dish (try not to pour it directly over the pastry initially, as this can make it soggy).
• Place the baking dish in the preheated oven. Bake for 40-50 minutes, or until the pastry is golden brown and cooked through, and the apples are tender when pierced gently with a fork or skewer near the core.
• Optional but Recommended: About halfway through baking (around 20-25 minutes), gently spoon some of the syrup from the bottom of the dish over the tops of the dumplings. This helps create a beautifully glazed crust. Repeat once or twice more during the remaining baking time.
• If the pastry starts to brown too quickly before the apples are tender, you can loosely tent the dish with aluminum foil.

7. Cool and Serve:

• Once baked, carefully remove the dish from the oven. Let the dumplings cool in the dish for at least 15-20 minutes before serving. The syrup will be extremely hot and will thicken slightly as it cools.
• Serve the dumplings warm, spooning generous amounts of the delicious syrup from the dish over each serving.