http://www.thelazymomcooks.com/2014/10/halloween-candy-croissants/

12 pieces Fun Size Dark Chocolate Bars
2 sheets Puff Pastry, thawed
1 Egg

Preheat oven to 400 F. Line two baking sheets with parchment paper.
While the first sheet of puff pastry is being worked, keep the other one in the refrigerator. Unfold the first sheet of pastry. Slice it lengthwise down the middle. Slice the two strips into three equal parts, making six squares.
Place one piece of chocolate toward the bottom of the chocolate. Wash one short end of pastry with egg. Fold the long sides in like a burrito, then roll the dough up over the chocolate. Continue with the remaining five squares.
Place the croissants on the baking sheet, then wash the top with egg wash. Bake for 15-18 minutes or until golden brown on top. While the first batch is baking, repeat the above steps on the second sheet of pastry. Cool croissants for five minutes before eating.