Whisk the dry ingredients. In a medium bowl, combine the plain flour, bicarbonate of soda, and salt. Whisk them together until evenly distributed — you'll see the pale flour mixture become slightly airy and uniform in colour. Set this aside.

Cream the butter and sugar. In a large bowl using a stand mixer fitted with the paddle attachment or a hand mixer, beat the softened butter and caster sugar on medium speed for 3-4 minutes. The mixture will turn from a yellow, grainy paste into a pale, fluffy, almost cloud-like texture. It should look light and feel silky when you rub a tiny bit between your fingers.

Add the wet ingredients. Beat in the egg, lemon juice, lemon zest, and vanilla extract on medium speed until fully incorporated. The batter may look slightly curdled at this stage — don't worry, that's the lemon juice reacting with the butter. It should smell intensely of fresh lemon and vanilla.

Combine wet and dry. Add the dry flour mixture to the wet mixture in two additions, mixing on low speed just until the flour disappears. Scrape down the sides of the bowl with a spatula — you want a soft, slightly sticky dough that holds together when pressed. The dough will feel tender and smell wonderfully citrusy.

Chill the dough. Cover the bowl tightly with cling film and refrigerate for at least 1 hour, or up to 3 days. Chilling firms the butter, preventing the cookies from spreading too much and helping the crinkle effect form. The dough will feel firm and cool to the touch when ready.

Preheat and prepare. Preheat your oven to 180°C (350°F) and line two baking trays with parchment paper. Place the icing sugar in a shallow bowl.

Roll and coat. Scoop chilled dough into 1½-tablespoon portions (about 30g each). Roll each portion into a smooth ball between your palms — the dough should feel cool and slightly tacky. Drop each ball into the icing sugar and roll around until completely coated. For the best crinkle effect, roll them generously so they look like little snowballs.

Bake to perfection. Place the coated dough balls 5cm apart on the prepared trays. Bake for 10-12 minutes. At 10 minutes, the edges will be set and lightly golden, while the centres will look puffy and slightly underdone with visible cracks forming across the tops. The kitchen will smell like a lemon grove.

Cool on the tray. Let the cookies rest on the hot baking tray for 5 minutes. They will continue to set and the crinkles will become more pronounced. The centres will look soft and slightly glossy through the cracks. After 5 minutes, transfer them to a wire cooling rack to cool completely.