Preheat oven to 180 C and place rack in centre of oven. Grease 20cm square pan and line bottom with baking paper

Melt chocolate and butter in large stainless steel bowl placed over simmering water. Remove from heat and stir in cocoa powder and sugar

Whisk in vanilla and eggs, one at a time, beating well after each addition. Stir in flour, salt and chocolate chips

Pour in pan and bake for 25-30 mins, or till toothpick inserted in centre comes out with a little batter and few moist clumps. Do not overbake!

Remove from oven and let it cool on wire rack. Serve with whipped cream or ice cream