Preparation Steps

• In a bowl whisk together cornstarch, flour, baking powder, and salt; set aside.
• Using a stand mixer, cream butter and sugar on medium speed until light and fluffy, about 30 seconds.
• Add egg yolks one at a time, mixing well after each addition, then stir in vanilla extract.
• Gradually add the dry ingredient mixture on low speed until a smooth dough forms.
• Shape the dough into a ball, wrap in plastic, and refrigerate for 30 minutes.
• Preheat oven to 350°F (177°C). Roll half the chilled dough on a lightly floured surface to about 0.2‑inch thickness.
• Cut circles with a 2‑inch cutter, place on parchment‑lined baking sheets, and bake for 10‑11 minutes until lightly golden.
• Cool cookies on a wire rack. Spread a thin layer of dulce de leche on the flat side of one cookie and sandwich with another.
• Roll the edges of each sandwich in shredded coconut, if using. Store in an airtight container.