Melt the unsalted butter in a microwave-safe bowl, heating it for 30 to 45 seconds until it’s almost fully liquid. Let it cool slightly while preparing your mixing bowl.

In a large mixing bowl, whisk together the all-purpose flour, baking soda, cornstarch, and kosher sea salt until thoroughly combined.

Using a mixer, combine the melted butter with granulated sugar and packed brown sugar. Beat on medium speed for about 1 minute until creamy, then add the fresh orange zest and vanilla extract.

Add the eggs, one at a time, allowing each egg to blend fully into the mixture before adding the next.

Reduce the mixer speed to low and gradually incorporate the dry ingredient mixture into the wet mixture. Mix just until a soft dough forms.

Using a spatula, gently fold in the chopped orange dark chocolate, ensuring it’s evenly distributed throughout the dough.

Cover the mixed dough and refrigerate it for 2 hours or, if desired, overnight.

About 15 minutes before baking, preheat your oven to 350°F (175°C) and prepare your baking sheets by lining them with parchment paper.

Once the dough is chilled, use a standard-size cookie scoop to portion out the dough onto the prepared baking sheets.

Place the baking sheets in the preheated oven and bake the cookies for 11 to 13 minutes or until the edges are a beautiful golden brown.

Once baked, remove the cookies from the oven and let them cool on the pan for 3 to 4 minutes before transferring them to a wire rack.