Prepare your workspace. Line two large baking trays with parchment paper. Set them aside. This small step means you won't be scrambling later when the dough is ready.

Cream the butter and sugars. In the bowl of a stand mixer fitted with the paddle attachment, beat the softened butter, brown sugar, and granulated sugar together on medium speed. Sensory cue: After about 3 minutes, the mixture will look pale, fluffy, and noticeably lighter in colour — almost like a thick, sandy paste. The sound will shift from a slosh to a soft, rhythmic slap.

Add the eggs and vanilla. Crack in the eggs one at a time, beating well after each addition. Pour in the vanilla extract. Sensory cue: The batter will become glossy and smooth, and you'll smell the warm, sweet aroma of vanilla cutting through the butter. It should look like a thick, shiny custard.

Combine the dry ingredients. In a separate bowl, whisk together the plain flour, bicarbonate of soda, and salt. Sensory cue: The flour will feel light and airy as you whisk; you'll see the salt and soda evenly distributed, with no white streaks remaining.

Mix the dry into the wet. With the mixer on low speed, gradually add the flour mixture to the butter mixture. Mix only until you can no longer see any dry flour. Sensory cue: The dough will pull away from the sides of the bowl and form a single, soft mass. It should be thick and slightly sticky to the touch, but not wet. Stop the mixer immediately — over-mixing will make the cookies tough.

Fold in the mix-ins. Using a sturdy spatula, fold in the rolled oats, milk chocolate chips, dark chocolate chunks, broken pretzel pieces, and coconut. Sensory cue: The dough will become studded with colour — the brown of the chocolate, the pale tan of the pretzels, the white flecks of coconut. You'll hear the gentle crackle of the pretzels as you fold. The dough will feel chunky and packed with texture.

Chill the dough. Cover the bowl with cling film and refrigerate for at least 30 minutes. This is non-negotiable. Sensory cue: After chilling, the dough will be firm to the touch and much less sticky. It will hold its shape when you scoop it. If you skip this step, the cookies will spread into thin, sad puddles.

Preheat and portion. Preheat your oven to 180°C (160°C fan). Scoop generous balls of dough — about 3 tablespoons each — and place them 10cm apart on the prepared trays. Sensory cue: The dough balls should be tall and rugged, not perfectly smooth. Press a few extra chocolate chips and pretzel pieces onto the tops for a prettier finish.

Bake to golden perfection. Bake one tray at a time for 14-16 minutes. Sensory cue: At the 12-minute mark, your kitchen will smell intensely of toasted oats and caramelised butter. The edges will be a deep golden brown, while the centres will still look pale and slightly puffed. The tops should be matte, not shiny. Do not over-bake — they will continue to set on the tray.

Finish with salt and cool. As soon as the tray comes out of the oven, sprinkle each cookie with a pinch of flaky sea salt. Let them cool on the tray for exactly 5 minutes. Sensory cue: The salt will glisten against the warm chocolate. The cookies will feel soft and fragile, but they will firm up as they cool. Transfer them to a wire cooling rack after 5 minutes.