Combine flour, butter, egg yolks, sugar, and lemon zest in a bowl. Mix quickly to form a dough. It will be slightly crumbly.

Shape the dough into a 2-inch diameter log, wrap in wax paper, and refrigerate for 30 minutes.

Preheat your oven to 400°F (200°C).

Slice the chilled dough into ½-inch pieces. Roll each piece into a rope about 4-5 inches long and shape into an “S.” Place on a parchment-lined baking sheet.

Add Finishing Touches:

Brush the cookies with beaten egg white and sprinkle with coarse sugar.

Bake for 15-20 minutes or until lightly golden. Cool on a wire rack.

Once cooled, dip half of each cookie in melted dark chocolate for an extra layer of indulgence.