Step 1: Make the Dough: Cream butter and sugar. Add egg yolks and lemon zest. Gradually mix in flour and cornstarch to form a dough. Chill for 1 hour.

Step 2: Bake the Cookies: Roll out the dough, cut into circles, and bake at 180°C (350°F) for 12-15 minutes. Let cool.

Step 3: Assemble: Spread dulce de leche on one cookie, then sandwich with another. Roll the edges in coconut flakes.

Step 4: Pro Tips:

Step 5: Chill the dough before rolling it out to make it easier to handle and to prevent the cookies from spreading too much while baking.

Step 6: Dip the alfajores in melted chocolate and let them set on a wire rack for an extra decadent treat.