Preheat oven to 350F.
In a small saucepan or a bowl in the microwave, melt the chocolate and butter over low heat. Stir until smooth and if you used a pot, pour into a bowl.
Stir in the sugar, vanilla and eggs; blend well. Add the flour, cocoa and salt and stir until almost combined; add the chocolate chips and stir just until blended.
Spread into a 9"x13" pan that has been lined with parchment or sprayed with nonstick spray; bake for 25-30 minutes, or until just set. (A toothpick inserted will come out with lots of moist crumbs sticking to it.)