Line a square baking tin with baking paper. Preheat your oven to 160°C
Mix the oil and cocoa powder together so that there are no lumps. Add the sugar, vanilla, eggs, flour, and baking powder and mix. Add the chocolate pieces and stir.
Pour into your baking tin and bake for 30 to 40 minutes. Allow to cool in the tin before cutting into squares.
Add the balsamic vinegar to a pot and bring to the boil. Add the raspberries and brown sugar and stir for 10 minutes while boiling. Remove from heat and wait for 5 minutes. Add the chocolate and stir. Allow to cool completely. Whip the cream and slowly add the balsamic mixture.
Serve the brownie and top with the balsamic, dark chocolate and raspberry sauce.
