1. Preheat oven to 350°F (180°C). Line a baking sheet with parchment paper.

2. In a large bowl, cream the softened butter and 60 g confectioners’ sugar until pale and fluffy, about 3 minutes.

3. Beat in the egg yolk until fully incorporated.

4. Gradually mix in the flour until a soft dough forms. Do not overwork.

5. Turn the dough onto a lightly floured surface and shape into a flat disc. Wrap in plastic and chill for 30 minutes.

6. Roll the dough to 6 mm (1/4 inch) thickness. Cut into rounds using a 5–6 cm (2–2.5 inch) cutter. Transfer to the baking sheet.

7. Bake for 12–15 minutes, until the edges just begin to turn golden. Cool completely on a wire rack.

8. In a clean bowl, whisk the egg white to stiff peaks.

9. Gradually add 30 g confectioners’ sugar, beating until smooth and glossy.

10. Flip half the cookies upside down and pipe or spread a small amount of the filling onto the flat side.

11. Top with remaining cookies, flat-side down, to create sandwiches.

12. Press gently to spread the filling slightly.

13. Sprinkle the tops with almond flakes and a light dusting of confectioners’ sugar.

14. Serve the same day for the best texture.