Ingredients :

• Butter — Use unsalted butter, not salted — the salt quantity in the dough is already balanced. No need for a premium brand, but avoid margarine or low-fat spreads, which alter the emulsion. 80g might seem little, but it’s plenty to give that characteristic milky taste.
• Eggs — This is the most critical ingredient. They must be at room temperature — taken out of the fridge 30 minutes ahead. Adding a cold egg to warm dough can cause it to curdle. Prefer medium size: large eggs risk making the dough too runny.
• Pearl sugar — Don’t even think of replacing it with regular sugar or brown sugar. Pearl sugar resists heat without fully melting — that’s its strength. It’s available in the baking aisle, sometimes labeled ‘hail sugar’. Brand Daddy or Alter Eco, doesn’t matter.
• Flour — All-purpose flour, the one you already have in your pantry. Cake flour also works. No need for special flour or sifting if your flour isn’t lumpy — a simple wooden spoon will do for incorporating.