Preheat oven to 180 ° C. Line a 5cm, 18cm (base) rectangular baking sheet with nonstick parchment paper.

Heat butter, chocolate and sugar in a saucepan over low heat, stirring constantly, until melted and smooth.  Transfer to a heat-resistant bowl.  Set aside to cool slightly.

Add eggs and vanilla to the chocolate mixture.  Mix and mix well.  Sift flour and cocoa powder over the chocolate mixture.  Stir so that it is well blended, I use a low speed mixer only for a while until it's blended.

Pour the batter into the pan.  Bake for 20 minutes or until cooked, then set aside until cooked.  Once cool, remove from heat and can be cut according to taste.  This brownie is cruncy on the outside and moist on the inside.  Suitable for afternoon tea and coffee ☕