Let Puff Pastry (1 package) thaw at room temperature until it's still cold but easy to work with.
Preheat oven to 200 degrees C (400 degrees F).
Flatten it into a large circle and divide circle into equal sized triangles.
Put a dollop of Nutella® (1) at the base of each triangle.
Roll triangle into croissant shape, making sure to seal the edges well so chocolate doesn't ooze out during baking.
Now pinch the tip of the triangle so that it sticks. That way the croissant won't come apart as the pastry puffs up in the oven.
Arrange croissants on a baking sheet and brush the tops with a little milk to give them a nice browned color as they bake.
Bake in preheated oven until they are nice and all puffed up. You'll have to eat these up on the same day because they won't keep well. Sorry, I know that will be difficult. Enjoy!