In a double-boiler over medium-high heat, or microwave, melt butter and chocolate until completely smooth. Cool slightly.
In a large bowl, whisk eggs, sugar, cooled chocolate mixture, and vanilla until smooth. Fold in flour, cocoa powder, and salt until a smooth batter forms. Fold in chocolate chips. Cover bowl with plastic wrap and refrigerate 30-60 minutes until slightly chilled.
Scoop batter by the tablespoonful and place 3 in apart on parchment paper-lined baking sheets. (cookies will spread quite a bit while they bake) Bake cookies at 350F 9-10 minutes or until beginning to crack on top (cookies will still be soft on inside---this is ok) Cool cookies on baking sheet 5 minutes, then transfer to a wire cooling rack to cool completely. Enjoy!