Pre-heat the oven to 180ºC. Line a baking sheet with baking parchment.
Mix the breadcrumbs and the coconut together and scatter over the baking parchment. Place in the oven for 4 - 5 minutes to toast, giving them a good shake halfway through. Tip into a shallow bowl or on a plate, ready to coat the prawns and add a pinch of salt.
Give the baking parchment a spray with low calorie cooking spray. You can use the same one that you used to toast the breadcrumbs.
Pat the prawns dry with some kitchen roll, then dip each one into the beaten egg, then into the breadcrumb and coconut mixture, pressing the crumbs on firmly so they stick. The breadcrumbs should cover the prawns in a light coating.
Lay the prawns on the baking parchment leaving a small gap between each one to make sure they cook evenly.
Give the coated prawns a quick spray with low calorie cooking spray and place in the oven for 8-10 minutes until crisp and the prawns are pink and opaque all the way through.
Serve, sprinkled with a little fresh coriander, lime wedges for squeezing and some sweet chilli sauce for dipping.