In a sturdy saucepan, melt the bittersweet chocolate chips along with the butter over low heat, stirring frequently until the mixture becomes smooth and well-blended. Once melted, remove from the heat and allow it to cool slightly.

In a stand mixer with the paddle attachment, whisk together the eggs, granulated sugar, light brown sugar, vanilla extract, baking powder, and salt. Beat on high speed for a full 5 minutes, or until the mixture becomes thick and creamy. This step is essential for achieving the right consistency, so ensure the time is followed precisely.

Lower the mixer speed, then gradually incorporate the melted chocolate mixture until it’s fully integrated and smooth.

Sift in the flour and cocoa powder, and gently fold them into the batter until just combined, ensuring not to overmix.

If using, stir in the chopped pecans and mini semisweet chocolate chips, making sure they’re evenly distributed. At this stage, the batter should resemble a thick, brownie-like texture.

Cover the batter and place it in the refrigerator to chill for 30 minutes. This helps the cookies maintain their shape during baking.

Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper for easy removal.

Using a 1.5-tablespoon cookie scoop, drop spoonfuls of the batter onto the prepared baking sheets, keeping them around 2 inches apart to allow room for spreading.

Bake for 8-10 minutes, or until the cookies appear set around the edges but still slightly glossy in the center. Be cautious not to overbake, as this could result in less fudgy, crackly cookies.

Allow the cookies to cool on the baking sheets, during which time the shiny, crackled crust will form as they set.