Preheat oven to 350°F (180 degrees C) and place the rack in the center of the oven. Butter (or spray with a nonstick cooking spray) an 8 inch (20 cm) square pan, and line the bottom of the pan with parchment or wax paper.

Melt the chocolate and butter in a large stainless steel bowl placed over a saucepan of simmering water. Remove from heat and stir in the sugar. - Next, whisk in the vanilla extract and eggs, one at a time, beating well after each addition. Finally, stir in the flour, salt, cocoa powder and chocolate chips (if you are using any).

Next, whisk in the vanilla extract and eggs, one at a time, beating well after each addition. Finally, stir in the flour, salt, cocoa powder and chocolate chips (if you are using any).

Pour into the prepared pan and bake for about 25-30 minutes, or until a toothpick inserted in the center comes out with a little batter and a few moist clumps clinging to it. Do not over bake. Remove from oven and let cool on a wire rack. Serve at room temperature or chilled. These freeze very well too and can be reheated before serving as per desire