Cream the butter and sugar: In a large mixing bowl, beat the softened butter, caster sugar, and lemon zest together on medium speed for 3-4 minutes. The mixture should turn pale yellow, look light and fluffy, and smell intensely of lemon. Scrape down the sides halfway through.

Add the wet ingredients: Beat in the eggs one at a time, mixing well after each addition until the batter looks smooth and glossy. Pour in the lemon juice and vanilla extract, then mix on low speed. The batter will look slightly curdled at this stage — that is perfectly normal and will resolve once you add the flour.

Combine the dry ingredients: In a separate bowl, whisk together the plain flour, bicarbonate of soda, and salt. Add the dry mixture to the wet batter in three additions, mixing on low speed until just combined. Stop as soon as you no longer see streaks of flour — overmixing will make the cookies tough. The dough should be soft, slightly sticky, and smell wonderfully of fresh lemon.

Chill the dough: Cover the bowl with cling film and refrigerate for at least 1 hour, or up to 24 hours. The dough needs this rest to firm up so you can roll it into balls without it sticking to your hands. After chilling, the dough should feel firm but still pliable, not rock hard.

Preheat and prepare: Preheat your oven to 180°C (fan-assisted) or 200°C (conventional). Line two large baking trays with parchment paper. Pour the icing sugar into a shallow bowl.

Shape and coat: Scoop rounded tablespoons of chilled dough (about 30g each) and roll them into smooth balls between your palms. Drop each ball into the icing sugar, rolling it around to coat thoroughly. The sugar coating is what creates the signature crinkle effect, so be generous — the dough should look completely white. Place the coated balls 5cm apart on the prepared trays. For a restaurant touch, press a tiny indent into the centre of each ball and add a dab of lemon curd before sealing with another small piece of dough.

Bake: Bake one tray at a time for 10-12 minutes. The cookies will spread, crack, and puff up slightly. You will know they are done when the edges are just set and lightly golden, the tops are covered in fine cracks, and the centres still look slightly soft and puffy. The kitchen will smell intensely of toasty lemon and butter.

Cool and finish: Let the cookies rest on the baking tray for 5 minutes — they will continue to set as they cool. Then transfer them to a wire cooling rack using a thin spatula. Once fully cool, dust with a final light snowfall of icing sugar through a fine sieve for that picture-perfect finish.