Preheat oven to 160 degrees (fan-forced). Grease and line baking trays with baking paper.
Place the plain flour, baking powder and bi-carb soda into the TM bowl. Sift by pressing Turbo 5-10 times. Set aside in a separate bowl.
Place the macadamia nuts into the TM bowl and roughly chop by pressing Turbo 4-5 times. Set aside.
Place the dried apricots into the TM bowl and finely chop by pressing Turbo 5-8 times. Set aside.
Cream the softened butter, brown sugar and caster sugar for 30 seconds on Speed 4. Scrape down the sides of the bowl and repeat until pale and creamy (approximately 1 more minute).
Reduce to Speed 2 and add the egg through the MC hole. Add the extra egg yolk and continue to mix on Speed 2.
Add the vanilla extract and the flour mixture and mix for 30 seconds, Speed 4 (using the spatula to assist).
When the dough is completely combined, add the rolled oats and mix for 30 seconds, Reverse, Speed 3 (using the spatula to help mix).
Fold through the chopped macadamia nuts and dried apricots.
Roll the mixture into heaped tablespoon-sized balls and place 3-4cm apart on the prepared trays. Press down lightly.
Bake for 12-15 minutes or until lightly golden around the edges.
Allow to cool on the baking trays for 10 minutes before moving to a wire rack to cool completely.
Drizzle melted white chocolate over the top of the cooled cookies with a knife. Store in an airtight container.