Preheat your oven to 180°C (160°C fan) and line a baking tray with parchment paper. The paper should release easily from the tray without sticking.

In a large mixing bowl, beat the softened butter, caster sugar, and light brown sugar together until the mixture looks pale and fluffy — this should take about 2 minutes with a wooden spoon. You'll notice the grains of sugar disappear into the butter, and the colour shifts from yellow to a creamy beige.

Crack the egg into the bowl and add the vanilla extract. Stir vigorously until the mixture turns smooth and glossy, and you can no longer see streaks of egg white. The batter should look thick and shiny.

Sift the plain flour, bicarbonate of soda, and salt into the wet mixture. Fold gently with a spatula or wooden spoon until just combined — stop as soon as you can't see any white flour streaks. Overmixing will make the cookies tough, so I stop the moment the dough looks uniform.

Fold in the white chocolate chips and chopped macadamia nuts. The dough will feel quite firm and slightly sticky at this stage. You should see the nuts and chocolate evenly distributed throughout.

Using a tablespoon or a small ice cream scoop, drop rounded balls of dough onto the prepared baking tray, spacing them about 5cm apart. Each ball should be roughly the size of a walnut. The dough will spread as it bakes, so don't crowd the tray.

Bake for 12-14 minutes, or until the edges turn a deep golden brown while the centres still look pale and slightly underdone. Your kitchen will fill with a buttery, nutty aroma when they're nearly ready. The tops should be just set but still soft to a gentle touch.

Remove the tray from the oven and let the cookies rest on the hot tray for 5 minutes. During this time, the residual heat finishes cooking the centres. You'll see the cookies firm up slightly as they cool.

Transfer the cookies to a wire cooling rack using a spatula. They will feel fragile at first but will crisp up as they cool completely. Leave them for 10 minutes before serving, if you can resist.