Preheat oven to 375°F. Line a large baking sheet with parchment paper.

On a lightly floured surface, unfold one sheet of the puff pastry. Use a rolling pin to roll the pastry into a 10x13-inch rectangle. Carefully transfer the pastry to the prepared baking sheet.

Spread your desired filling over the pastry, making sure to get to the edges.

Roll the second sheet of puff pastry into a 10x13-inch rectangle. Place it on top of the first sheet, sandwiching the filling between the two layers of pastry.

Using a sharp knife or pizza cutter, cut the pastry into a large triangle. Set aside the trimmed corners; do not discard. If desired, cut out a trunk shape from the bottom of the triangle, setting aside the trimmed pieces.

Now, starting from the bottom of the triangle, cut into the tree at 1-inch intervals, leaving an uncut strip of about 1 inch down the center for the trunk. Leave the top 3 inches of the tree uncut, since those pieces would be too small to twist.

Carefully twist each strip; twist longer strips 3 times and the shorter pieces at the top of the tree 1-2 times.

Cut the scraps into strips. Twist them and place them on a separate baking sheet (you can place them on the edges of the first pan if it is large enough, just make sure they don’t touch the tree). Brush with the egg wash.

If using a savory filling, lightly sprinkle the top of the tree and extra strips with a bit of flaky sea salt.

Bake for 20-25 minutes, until the top is deeply golden and the bottom is cooked through.

Let cool for 5-10 minutes. Dust with powdered sugar if using a sweet filling or top with freshly grated parmesan cheese if using a savory filling.