Preheat oven to 375 degrees. Lightly butter a 23 cm diameter circle in the center of a baking sheet.
In a large bowl, stir together the flour, sugar, baking powder, and salt. Cut the butter into 1 cm cubes and distribute them over the flour mixture. With a pastry blender or two knives used scissors fashion, cut in the butter until the mixture resembles coarse crumbs. In a small bowl, stir together the milk, egg, and vanilla. Add the milk mixture to the flour mixture and stir to combine. Stir in the papaya, pineapple, macadamia nuts, coconut, and white chocolate until evenly distributed.
With lightly floured hands, pat the dough into a 20 cm circle in the center of the prepared baking sheet. With a serrated knife, cut into 8 wedges. Bake for 18-20 minutes, or until the top is lightly browned and a cake tester or toothpick inserted into the center of a scone comes out clean.
Remove the baking sheet to a wire rack and cool for 5 minutes. Using a spatula, transfer the scones to a wire rack to cool. Recut into wedges, if necesary. Serve warm, or cool completely and store in an airtight container. These freeze well.