Make the sweet almond paste by adding the ingredients
in a small pan and melting them over a low heat: this won't
take long and the almonds will burn unless you stir pretty
much continuously (the order ensures they are on the top).
Slice open the croissant across the middle, from the
non-hinge side, leaving a little of the hinge connected if you
Apply the paste evenly over the sliced surface of one half
of the croissant, getting right to the edges.
Close the croissant and cook on a baking tray in the oven
for 5 minutes.