Preheat oven to gas mark 3 / 165*C / 325F.
Line a 30x20x4 baking tin using Bakewell Siliconised non-stick baking paper.
In a large bowl stir together 300g caster sugar and 170g of melted butter. When mixed add 55g of cocoa powder and 2-3 drops of vanilla extract. Stir well.
One at a time add to the mixture 3 eggs and stir till a smooth consistency is obtained.
Sift into the mixture 170g of plain flour and a pinch of baking powder, stirring well add 100g of chocolate chips.
When the mixture is a smooth consistency carefully spoon the mixture into the prepared tin. Spread mixture to the corners of the tin and level out the surface using a spatula.
Bake in the oven for 30-35 minutes.
When cooked remove the tin from the oven and leave to cool on the side.
When completely cooled cut the brownies into squares and enjoy 🙂