1. Make the Dough:

• In a large bowl, whisk together the flour, granulated sugar, and salt.
• Add the chilled butter and mix with a pastry cutter or your fingers until the mixture resembles coarse crumbs.
• Stir in the cold water, one tablespoon at a time, until the dough comes together. Divide the dough into two disks, wrap in plastic wrap, and refrigerate for at least 30 minutes.

2. Prepare the Filling:

• In a bowl, combine the pumpkin puree, brown sugar, pumpkin pie spice, salt, and vanilla extract. Mix until well combined. Set aside.

3. Roll Out the Dough:

• Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
• On a floured surface, roll out one disk of dough to about 1/8 inch thick. Cut into rectangles (about 3×4 inches) for the base of the pop-tarts. Repeat with the second disk.

4. Assemble the Pop-Tarts:

• Place half of the rectangles on the prepared baking sheet. Spoon about 1 tablespoon of the pumpkin filling onto the center of each rectangle.
• Brush the edges with a little water, then top with another rectangle of dough. Press the edges together with a fork to seal.

5. Bake:

• Cut small slits in the top of each pop-tart to allow steam to escape. Brush the tops with the beaten egg.
• Bake for 20-25 minutes, or until golden brown. Remove from the oven and let cool.

6. Glaze:

• In a bowl, whisk together the powdered sugar, milk, and vanilla extract until smooth. Drizzle over the cooled pop-tarts and add sprinkles or nuts if desired.