Preheat Oven: Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.

Melt Chocolate and Butter: In a microwave-safe bowl, combine the semi-sweet chocolate chips and unsalted butter. Microwave in 30-second intervals, stirring between each, until the chocolate and butter are melted and smooth.

Mix Wet Ingredients: In a large mixing bowl, whisk together the granulated sugar, eggs, and vanilla extract until well combined. Stir in the melted chocolate mixture.

Combine Dry Ingredients: In a separate bowl, whisk together the flour, baking powder, cocoa powder, and salt. Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Add Chocolate Chips: Gently fold in the additional chocolate chips.

Scoop and Bake: Using a cookie scoop or spoon, drop tablespoons of dough onto the prepared baking sheet, spacing them about 2 inches apart. Bake in the preheated oven for 10-12 minutes, or until the edges are set but the centers are still slightly soft.

Cool: Allow the cookies to cool on the baking sheet for about 5 minutes before transferring them to a wire rack to cool completely.

Enjoy your rich and fudgy Brownie Cookies!