In a large bowl, add the sugar and lemon zest.
Rub the zest into the sugar using your fingers until it becomes fragrant and slightly moist. This helps release the essential oils and intensifies the lemon flavor.
Add a small pinch of turmeric for a natural yellow color (optional).
Add the softened butter.
Beat together with the lemon sugar until light and creamy, about 2–3 minutes.
Mix in the eggs, one at a time, beating well after each addition.
Add the lemon juice and vanilla extract. The mixture may look slightly curdled at this stage—this is perfectly normal.
In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet mixture, mixing just until combined. Do not overmix.
If using, gently fold in the white chocolate chips or chunks.
Cover the dough and chill for at least 1–2 hours. This step is essential for thicker cookies and well-defined crinkles.
Preheat the oven to 350°F (180°C) and line baking trays with parchment paper.
Scoop the dough into equal portions (about 20 g each) and roll into balls.
Roll each ball generously in powdered sugar.
Place on the prepared baking sheet, leaving 2 inches (5 cm) of space between each one.
Bake for 10–12 minutes, until the cookies have spread, developed cracks, and remain pale on top.
Cool on baking sheets for 5-10 minutes. Remove to cooling rack to cool completely.