Preheat and prep: Heat oven to 350°F. Line two baking sheets with parchment paper.

Mix the wet ingredients: In a large heatproof bowl, whisk the brown sugar into the warm melted butter until glossy. Let it sit for 3–4 minutes to cool slightly. Beat in the egg, yolk, and vanilla until smooth.

Combine the dry: In a separate bowl, stir together the flour, cocoa powder, baking soda, and salt.

Bring the dough together: Add the dry mixture into the wet ingredients and stir gently until no streaks of flour remain. Fold in the coconut, pecans, and chopped chocolate.

Scoop and bake: Drop rounded spoonfuls of dough (about 1½ tbsp each) onto the prepared baking sheets, spacing 2 inches apart. Bake 10–12 minutes, until edges are firm but centers still look soft.

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