Preheat your oven to 350°F (175°C) and line your baking sheets with parchment paper.

In a mixing bowl, combine softened unsalted butter with granulated and brown sugars and beat until light and fluffy.

Add the egg, pure vanilla extract, and freshly grated orange zest to the mixture and beat until well combined.

In a separate bowl, whisk together all-purpose flour, baking soda, and salt.

Gradually add the flour mixture to the wet ingredients, stirring gently until just combined.

Fold in the dark chocolate chunks until evenly distributed.

Drop rounded balls of dough onto the prepared baking sheets, leaving space between each ball.

Bake for 9–11 minutes or until the edges are golden and the centers are soft.

Allow the cookies to cool on the baking sheets for about 5 minutes before transferring to a wire rack.