In a medium bowl, combine the pumpkin puree, brown sugar, granulated sugar, ground cinnamon, ground nutmeg, and vanilla extract. Mix thoroughly until smooth and well-blended. Cover and refrigerate for 15 to 30 minutes.

On a floured surface, roll out the puff pastry sheet to approximately 10 by 12 inches. Slice into six 4 by 5 inch rectangles.

Place about a tablespoon of the chilled pumpkin filling in the center of each rectangle. Fold the rectangle in half over the filling and press edges to seal tightly. Twist to form a spiral shape.

Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper and place the twists on it, spacing them apart. Brush the tops with an egg wash.

Bake for 15 to 20 minutes, or until golden brown and puffed. Monitor closely towards the end.

Let cool on a wire rack for a few minutes before serving. Drizzle with cream cheese frosting or dust with powdered sugar if desired.