1Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a medium bowl, whisk together the all-purpose flour, cocoa powder, baking soda, and salt. Set aside.
In a large bowl, beat the unsalted butter, granulated sugar, and brown sugar together until light and fluffy.
Add the large egg and vanilla extract to the butter mixture and beat until well combined.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the semi-sweet chocolate chips.
Drop rounded tablespoons of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake for 10-12 minutes, or until the edges are set but the centers are still soft.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.
Enjoy your delicious Double Chocolate Cookies!