Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.

Whisk together the flour, cocoa powder, baking soda, and salt in a medium bowl until evenly combined. Set aside.

In a large bowl, cream the softened butter with the brown sugar and granulated sugar on medium speed for 2–3 minutes until pale and slightly fluffy.

Beat in the egg and vanilla until fully incorporated and smooth.

Gradually add the dry ingredients to the wet, mixing at low speed just until no streaks of flour remain.

Fold in the chocolate chips, caramel pieces, and chopped pecans with a spatula.

Drop rounded tablespoonfuls of dough onto the prepared baking sheet, leaving about 2 inches between each cookie.

Bake for 10–12 minutes, until edges are set and centers look slightly soft.

Let the cookies cool on the baking sheet for 3–5 minutes, then transfer to a wire rack to cool completely.