Preheat oven to 180°C/350°F/Gas Mark 4. Grease and line a 28 x 18cm (11 x 7 inch) baking tin.
Place butter and broken pieces of Extra Dark Chocolate in a heatproof bowl. Place bowl over a saucepan of gently simmering water. Heat gently, stirring occasionally, until melted.
Remove bowl from water and stir in sugar. Cool for 10 minutes then whisk in eggs. Sieve in flour and add Vanilla Extract, Dark Chocolate Chips and pecans. Gently fold ingredients into melted chocolate mixture.
Spoon into prepared tin, smooth top and bake for 35 – 40 minutes until firm. Cool completely, cut into 12 portions.
Top with melted chocolate and add your own decorations to finish.