Bring a medium stockpot of lightly salted water to the boil. Cook prawns 2 to 3 minutes, or until opaque. Drain, allow to cool slightly and pat dry with kitchen roll. Peel, devein and slice in half.
Bring another stockpot of lightly salted water to the boil. Poach pork at a low boil for approximately 10 minutes, to an internal temperature of 70 C. Allow to cool, and slice into thin strips.
Again, bring a stockpot of water to the boil. Cook rice noodles until tender, stirring occasionally, approximately 7 to 8 minutes. Strain, and rinse well to prevent sticking.
Fill a medium bowl with warm water. Dip each wrapper in water for about 30 seconds until soft and flexible. Lay wrapper on a flat surface, and place 2 basil leaves in centre, side by side, about 5cm (2 in) from edge of wrapper. Lay 4 to 5 prawns halves on basil, followed by a small amount of pork, then a small amount of noodles. Sprinkle with coriander, mint, and top with beansprouts. Starting at one end, roll the wrapper over once, fold both sides in toward centre, and continue rolling as tightly as possible without tearing. The end result should be a roll approximately 3 to 4cm (1 to 1 1/2 in) thick.
Warm hoisin sauce, peanut butter and water in a saucepan over medium high heat. Bring to the boil, and immediately remove from heat. Garnish sauce with chopped peanuts, if desired, and serve with rolls for dipping.