Make the dough: In a large mixing bowl, combine the gluten-free flour, sugar, and salt. Add the chilled butter and cream cheese. Use a pastry cutter or your fingers to blend until it resembles coarse crumbs. Add the vanilla extract and 1 tablespoon of cold water. Mix until the dough begins to come together. If the dough is too dry, add the remaining cold water. Shape the dough into a disk, wrap it tightly in plastic wrap, and refrigerate for at least 1 hour.

1. Prepare the filling: In a small bowl, combine the chocolate chips, sugar, cinnamon, and chopped nuts (if using). Set aside.
2. Assemble the rugelach: Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper. Take the chilled dough out of the fridge and divide it into 4 portions. Roll one portion of dough into a circle about 1/8-inch thick. Spread a thin layer of the chocolate mixture over the dough, leaving a small border. Slice the dough into 8 wedges and carefully roll each wedge from the outer edge towards the center. Place them on the prepared baking sheet.
3. Bake the rugelach: If using an egg wash, whisk the egg and brush the tops of the rugelach. Sprinkle with sugar and cinnamon. Bake for 18-22 minutes, or until golden brown and crisp on the edges. Let cool on the baking sheet for a few minutes before transferring to a wire rack.