Melt choc and butter, mix in sugar and vanilla, then eggs. Stir in flour, cocoa and salt, bake in lined 20cm/8" pan at 180°C/350°F (160°C fan) for 28 minutes. Cool before slicing.

Preheat oven to 180°C/350°F (160°C fan-forced). Spray a 20cm/8" square tin with oil or grease with butter. Line with baking paper/parchment paper with overhang (Note 3).

Melt chocolate and butter - Place butter and chocolate chips in a heatproof bowl, microwave in 30 second bursts (takes me 1m 30 sec) until melted. Stir until smooth.

Sugar and eggs - Add sugar and vanilla, mix, then add eggs and mix well until smooth and molten.

Dry ingredients - Add flour, cocoa and salt and stir until smooth. Stir in chopped chocolate, pour into pan.

Bake 24 minutes for really gooey in the centre, 28 minutes for fudgey but still very moist (my favourie, shown in video & photos), 32 minutes for moist fudge-cake-like. (See in post for toothpick testphotos).

Rest for 10 minutes before lifting out of the pan (they are fragile when hot). Allow to cool for at least 20 minutes before cutting. For really neat slices, refrigerate for 30 minutes, or even overnight, but always eat at room temp for fudgy perfection!