Lightly grease a baking tray. On a
floured surface, roll out the puff pastry to a rectangle of about
38x23cm.
Spread the chocolate hazelnut spread
over the pastry and scatter the chopped hazelnuts over the top.
Roll up one long side of the pastry to
the centre, then roll up the other side so that they meet in the
centre.
Where the pieces meet, dampen the edges
with a little so that it will join. Using a sharp knife, cut into thin
slices. Place each slice on to the prepared baking tray and flatten
slightly with a palette knife. Sprinkle the slices with the castor
sugar.
Bake in a preheated oven at 220 degrees
Celsius or until golden brown. Allow to cool on wire rack.