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

In a large bowl, cream the butter and sugar until light and fluffy (3-5 minutes).

Melt the dark chocolate and let it cool slightly before adding to the creamed mixture.

In another bowl, sift together flour, cocoa powder, and salt; gradually incorporate into the wet ingredients until just combined.

Scoop tablespoon-sized portions onto the prepared baking sheet, spacing them two inches apart.

Bake for 12-15 minutes until edges are firm but centers remain soft; cool on wire rack.