Steps
- Mix 200g of all-purpose flour, 300g of cornstarch, 2 teaspoons of baking powder, and 1 pinch of salt.
- Beat 250g of softened unsalted butter, 150g of superfine sugar, and the zest of 1 lemon until very pale.
- Beat in 3 large egg yolks, 1 tablespoon of cognac, and 1 teaspoon of vanilla extract. Mix in the dry ingredients to form a smooth dough. Wrap and refrigerate for at least 1 hour.
- Roll on a lightly floured surface to about ⅛in / 3mm thick. Cut into 2in / 5cm rounds and place on lined baking sheets. Chill for 20 minutes while the oven preheats to 350°F / 180°C.
- Bake for about 8 minutes, until set but still pale. Cool completely.
- Sandwich pairs of cookies with 450g of dulce de leche. Roll their edges in 50g of desiccated coconut.