Directions
<ol class="no-list-style"><li class="MethodStepper"><h4 class="step-title">Step 1</h4>Prepare the cookie dough by creaming the softened butter with both sugars in a stand mixer until light and fluffy, about 3-4 minutes. This creaming process incorporates air, creating a lighter texture in the finished cookie center.</li><li class="MethodStepper"><h4 class="step-title">Step 2</h4>Add the egg and vanilla extract to the butter-sugar mixture and beat until fully incorporated and smooth, scraping down the sides of the bowl as needed.</li><li class="MethodStepper"><h4 class="step-title">Step 3</h4>In a separate bowl, whisk together the flour, cocoa powder, baking soda, and salt. Gradually add this dry mixture to the wet ingredients on low speed until just combined - overmixing will develop too much gluten, resulting in a tough cookie center.</li><li class="MethodStepper"><h4 class="step-title">Step 4</h4>Fold in the chocolate chips or chunks by hand using a spatula. Cover the cookie dough and refrigerate for 30 minutes to firm up slightly, making it easier to handle.</li><li class="MethodStepper"><h4 class="step-title">Step 5</h4>Preheat your oven to 180°C and line two baking sheets with parchment paper. Remove the croissant dough from the refrigerator about 10 minutes before using so it's pliable but still cool.</li><li class="MethodStepper"><h4 class="step-title">Step 6</h4>On a lightly floured surface, gently roll out the croissant dough sheets to even out any folds, being careful not to compress the layers too much. Using a 10cm round cookie cutter, cut out 8 circles from each sheet (16 circles total).</li><li class="MethodStepper"><h4 class="step-title">Step 7</h4>Take the chilled cookie dough and divide it into 8 equal portions. Roll each portion into a ball, then flatten into discs about 8cm in diameter - slightly smaller than your croissant circles.</li><li class="MethodStepper"><h4 class="step-title">Step 8</h4>Place one cookie dough disc in the center of a croissant dough circle. Brush the edges of the croissant dough lightly with beaten egg, then place another croissant circle on top. Gently press the edges to seal, being careful not to tear the delicate dough.</li><li class="MethodStepper"><h4 class="step-title">Step 9</h4>Using your fingers, crimp the edges firmly to create a secure seal all the way around. If any tears form, gently pinch them closed. The tight seal prevents cookie dough from leaking during baking.</li><li class="MethodStepper"><h4 class="step-title">Step 10</h4>Transfer the assembled crookies to the prepared baking sheets, spacing them at least 5cm apart as they will expand. Chill the assembled crookies in the refrigerator for 15 minutes - this helps maintain the defined layers during baking.</li><li class="MethodStepper"><h4 class="step-title">Step 11</h4>Just before baking, brush the tops of each crookie with beaten egg for a golden, shiny finish. Using a small sharp knife, make a tiny vent hole in the center of each to release steam during baking.</li><li class="MethodStepper"><h4 class="step-title">Step 12</h4>Bake for 22-25 minutes until the croissant exterior is deeply golden and flaky. The cookie center should remain slightly soft - it will continue cooking from residual heat after removal from the oven.</li><li class="MethodStepper"><h4 class="step-title">Step 13</h4>Allow the crookies to cool on the baking sheets for 10 minutes before transferring to a wire rack. Just before serving, dust lightly with powdered sugar. Crookies are best enjoyed warm while the chocolate chips are still melty, but they'll keep in an airtight container for 2 days.</li></ol>