Pre-heat the oven to 200°C / 392°F.
Roll out one puff pastry sheet on a baking tray lined with parchment paper.
Spread the Nutella on top of the pastry with a palette knife or the back of a spoon.
Top with the second pastry sheet.
Pat the two sheets together.
Cut a symmetrical indent at the bottom to make the tree trunk (save these pieces for the presents).
Trim two 1 cm thick strips into the dough at the top, keeping the middle intact.
Cut a triangular shape underneath the middle of the top strips and the outer trunk indent.
Trim five sections along the edge of the tree to each side. Leave the section above the tree trunk intact.
Fold over the top corners of each section.
Shape the star out of the top strips.
Make the square presents using the trimmed-off pastry. You can cut thin pieces to make ribbons and bows (press these into the squares) or leave the presents plain.
Arrange the gifts underneath the tree.
Beat the egg in a small bowl. Brush the pastry with egg wash. Top with pearl sugar.
Bake the tree in a 200°C / 392°F oven for approximately 15 minutes until golden brown.
Dust with powdered sugar, once cool.
Melt the dark chocolate and place it in a piping utensil or bag.
Pipe a swirled chocolate pattern on top of the tree.
Allow the chocolate to set.
Serve.