1.Soak noodles in bowl of water; drain. Roughly chop noodles.
2.Place noodles in medium bowl with wombok, mint, sugar and juice; toss to combine.
3.Shell and devein prawns; finely chop meat.
4.Make hoisin dipping sauce. Combine ingredients in bowl.
5.Dip one rice paper round in a bowl of warm water until soft; place on board covered with clean tea towel Spoon some noodle filling on rice paper, leaving enough room on either side; top filling with some prawn meat. Fold rice paper up to cover the filling, roll to just cover filling. Fold in the sides, then roll to completely enclose. Repeat with remaining rice paper, noodle filling and prawn meat.
6.Serve rolls with dipping sauce.