In a medium bowl beat together the butter, almond paste and sugar until smooth. Add the eggs, one at a time, beating until incorporated before adding the next.
Stir in the almond extract.
Add the flour, one tablespoon at a time, mixing well.
For Croissants
Roll out the puff pastry on a lightly floured board. Cut lengthwise into triangles or cut into equal sized rectangles. Place a good sized teaspoonful of pastry cream on the wide end then roll up from the wide bottom to the top. Seal the ends and use a little water to secure the point. Shape into a crescent and place on the prepared baking sheet.
Mix the egg with the milk and brush over the croissant. Sprinkle some sliced almonds on top of the croissant.
Bake 18-20 minutes until puffed and brown.
Cool on a rack then finishing with a dusting of icing sugar.
For Pain Aux Amandes (Almond Bread)
Roll out the puff pastry as above. Cut into rectangles. Place the almond cream on the long side of each rectangle then fold over three times. Seal the ends and put the pastry on the baking sheet with the sealed end down.
Recipe Notes
Makes 12 large or 24 small croissants, or 16 Pain Aux Amandes