Line a baking sheet with plastic wrap. Place one won ton wrapper on a work surface. Brush the edges of the won ton wrapper with egg. Spoon one tablespoon of chocolate hazelnut spread into the center of the wrapper. Fold the wrapper diagonally in half over the filling and press the edges to seal. Place the ravioli on prepared baking sheet. Repeat with remaining wrappers, spread and egg.
Preheat oven to 200 degrees. Add enough oil to a heavy large frying pan to reach a depth of two inches. Heat the oil over medium heat to 350 degrees.
Working in small batches, carefully add the ravioli to the hot oil and cook until they are golden brown, about 45 seconds per side. Using a slotted spoon, transfer the ravioli to a plate lined with paper towels to drain. Then transfer the ravioli to another baking sheet and keep warm in the oven while frying the remaining ravioli. (The fried ravioli can be prepared one day ahead. Cool them completely, then cover and refrigerate. Before serving, place them on a baking sheet and rewarm in a preheated 375 degree oven until they are heated through. about 7 minutes.]
Dust the warm ravioli with powdered sugar and enjoy.