Place the sugar and water in a medium sized saucepan and stir over low heat to dissolve the sugar completely. Increase the heat and boil the mixture for approximately 5 minutes, until it thickens slightly and starts to turn a golden colour. Reduce the heat to a simmer and add the strawberries. Continue to simmer for 15 minutes, stirring occasionally, until the mixture is a thick, jam-like consistency. Remove from the heat and set aside to cool.
Chill an ice cream maker bowl according to the manufacturer’s instructions. Place the macadamias and water in a high-speed blender and blend for 2-3 minutes. Strain through a nut bag and pour into a medium sized saucepan. Add the remaining ingredients and stir over a medium heat to dissolve the sugar. Remove from the heat and pour into a large pouring jug. Refrigerate until cold.
When completely cool, add the strawberry flavour and stir to combine. Pour into the bowl of the chilled ice cream maker and churn until chilled and thick. Freeze until ready to serve. Serve in cones if desired.