Preheat your oven to 180°C (350°F).
Line a cookie sheet with parchment paper.
In a large mixing bowl, cream together the butter, muscovado sugar, and caster sugar until light and fluffy, about 3-4 minutes.
Add the egg and vanilla extract, beating until well combined and smooth.
In a separate bowl, whisk together the flour and baking powder. Gradually add to the wet ingredients, mixing until just combined.
Fold in the white chocolate chunks, dried cranberries, and chopped macadamia nuts until evenly distributed.
Scoop rounded balls of dough onto the prepared baking sheet, leaving space between each cookie.
Bake for 10-12 minutes, until edges are lightly golden and centers look set but slightly soft.
Cool on the baking sheet for 5 minutes, then transfer to a cooling rack to cool completely.
