- With the rack in the middle position, preheat the oven to 400°F (200°C).
- On a lightly floured surface, roll out the dough into a 12-inch (30 cm) square with a thickness of 1/8 inch (3 mm). Place the dough on a sheet of parchment paper.
- Using a knife, cut horizontal strips 3 1/2 inches (9 cm) long, at 1/2-inch (1.5 cm) intervals all along the two opposite sides (left and right) of the dough. Set aside.
- In a bowl, whisk together the cream cheese, egg yolk and 2 tbsp of the sugar until smooth. Spread over the centre of the dough.
- In another bowl, toss the plums with 1 tbsp of the sugar. Place evenly over the cream cheese.
- Fold the strips over the filling, alternating left and right and overlapping to create a braid. Using a sliding motion, gently transfer the tart and parchment paper to a baking sheet.
- In a small bowl, beat the egg white with 1 tbsp of the sugar. Brush over the tart. Sprinkle with the remaining sugar.
- Bake for 30 minutes or until golden brown. Let cool for 15 minutes before serving
A good-looking braided tart starts with strips of dough that are the same width and length. Use a ruler to make straight cuts a real cinch.