For lime dipping sauce, combine ingredients in a small bowl, whisk to combine, until sugar dissolves and refrigerate until required.
Process shallots, garlic and lemon grass in a food processor until finely chopped.
Add prawn meat, palm sugar, egg white, fish sauce and cornflour and process until combined (do not overwork).
With wet hands, divide the mixture evenly into 10 and wrap around the sugarcane to form a cylinder about 4cm long. Place on a tray, repeat with remaining mix and sugarcane, cover and refrigerate to set (30 minutes - 1 hour).
Heat large pan over medium high heat, brush sugarcane prawns with oil, fry turning occasionally until cooked through (8-10 minutes).
Serve hot with butter lettuce leaves for wrapping, herbs and dipping sauce and fresh lime.