Cream the Butter and Sugars: In a large bowl, using an electric hand mixer or a stand mixer with the paddle attachment, beat the softened butter, light brown sugar, and granulated sugar together on medium speed for about 3-4 minutes. You're looking for a light, pale, and fluffy texture. This step is crucial for the final cookie structure, as explained well on Serious Eats.

Add Wet Ingredients: Add the egg and vanilla extract to the creamed mixture and beat again for another minute until everything is well combined. Scrape down the sides of the bowl to ensure it's all incorporated.

Combine Dry Ingredients: In a separate bowl, whisk together the plain flour, bicarbonate of soda, baking powder, and salt. This ensures the leavening agents are evenly distributed.

Mix the Dough: Gradually add the dry ingredients to the wet ingredients, mixing on a low speed until just combined. What works best for me is adding the flour in three additions. Be careful not to overmix at this stage.

Fold in the Good Stuff: Using a spatula, gently fold in the rolled oats, desiccated coconut, chopped pecans, and dark chocolate chips. The dough will be thick and chunky.

Chill the Dough: Cover the bowl with cling film and refrigerate for at least 30 minutes (or up to 24 hours). This is my non-negotiable step! It prevents the cookies from spreading too much in the oven, resulting in a thicker, chewier cookie.

Preheat and Prepare: While the dough is chilling, preheat your oven to 180°C (160°C fan) and line two large baking sheets with parchment paper.

Scoop and Bake: Use a medium ice cream scoop or two tablespoons to portion out balls of dough (about 40g each). Place them on the prepared baking sheets, leaving about 5cm of space between each one to allow for spreading.

Bake to Perfection: Bake for 12-15 minutes, or until the edges are golden brown but the centres still look slightly soft. They will continue to firm up as they cool on the baking sheet.

Cool Down: Let the cookies cool on the baking sheets for 5-10 minutes before transferring them to a wire rack to cool completely. This helps them set properly.