Instructions

1. Pre-heat oven to 180°C/350°F/gas 4 and line a 23x23cm (9x9inch) deep square baking tin with parchment paper.
2. Put the chocolate and butter in a heat proof bowl and sit it over a pot of barely simmering water to melt, stirring occasionally. When nearly completely melted, add the sugar and stir to combine. Remove from heat and leave to cool for 5-10 minutes.
3. Beat in the eggs, one at a time, making sure each is well mixed in before adding in the next.
4. Sift in flour and cocoa and mix in, then mix in the vanilla.
5. Fold in half of the raspberries then pour batter into prepared baking tin, smooth the top with a spatula or back of a spoon. Scatter the remaining raspberries over the top and bake for 30 minutes, slightly longer if you want a slightly firmer texture.
6. Remove from oven and leave to cool completely on a wire rack still in the baking tin. Once cooled, remove from tin and use a sharp knife to cut into squares. For clean slices, heat the blade of the knife in boiling water then wipe dry before cutting. Do this after each cut.
7. Will keep for up to 3 days in an airtight container.