Here's what you'll need:
2 sheets frozen puff pastry, thawed
nutella
egg wash (1 egg + 1 tbsp water)
First, thaw out the puff pastry sheets and cut each sheet into 6 equal rectangles. On each square, add about a tablespoon of nutella.
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Next, wet the edges of each square of pastry, fold it over and press the edges together with a fork. Once ever rectangle has been folded and pressed and placed on a cookie sheet, pierce each piece a couple of times with a fork and brush on your egg wash.
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Place in a 400 degree oven for about 16 minutes (start watching them at 10 minutes just incase your oven is a bit hotter than mine). Once golden brown on the top, take them out of the oven, dust with powdered sugar and eat.
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I of course chose to fill my pastry with nutella, but I'm sure you could substitute a little bit of chocolate heaven for something else - jam, fruit, even something savory might be fun to try.