Preheat the Oven:
Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper.
Melt Butter and Chocolate:
In a microwave-safe bowl, melt the butter and 1 cup of the chocolate chips in 30-second intervals, stirring in between until smooth. Set aside to cool slightly.
Mix Wet Ingredients:
In a large mixing bowl, combine the granulated sugar, brown sugar, eggs, and vanilla extract. Beat with an electric mixer on medium speed until light and fluffy.
Combine Chocolate Mixture:
Gradually add the melted chocolate mixture to the egg mixture, beating until well combined.
Mix Dry Ingredients:
In a separate bowl, whisk together the flour, cocoa powder, baking powder, and salt.
Combine Wet and Dry Ingredients:
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Stir in the remaining 1/2 cup of chocolate chips and chopped peanuts.
Scoop and Bake:
Drop tablespoon-sized mounds of dough onto the prepared baking sheets, spacing them about 2 inches apart. Sprinkle a small pinch of sea salt flakes on top of each cookie.
Bake the Cookies:
Bake in the preheated oven for 10-12 minutes, or until the edges are set but the centers are still soft. Do not overbake.
Cool and Serve:
Allow the cookies to cool on the baking sheets for about 5 minutes before transferring them to a cooling rack to cool completely.