Put the oil in a large, heavy-bottomed pot, 1/3 full and heat to 350 degrees F. Prepare a baking tray lined with paper towel. Put the wonton wrappers on a clean dry working surface and brush with egg wash. Put 1/4 teaspoon jam in the center of each wonton. Gently lift the edges of the wonton up and twist, creating a parcel and pinch tightly around the base to secure. In batches, place the wontons in the hot oil to fry until golden brown. Once the parcels are golden brown, remove them to the paper towel-lined tray to drain the excess oil. Repeat with the remaining wonton parcels. Once the jam parcels have cooled slightly, dust with icing sugar (confectioners') and serve.