Preheat your oven to 160°C and line an 8x8-inch tin with baking paper.
Melt the dark chocolate and the butter together over low heat on the stove then set aside to cool for around 5 minutes.
Add the sugar, eggs and vanilla extract to a large bowl. Using an electric whisk, whisk it all together for a few minutes until it becomes pale and has doubled in volume.
Fold the melted butter/chocolate mixture into the whisked egg/sugar mixture. Then add the flour and the cocoa powder. Mix gently until well combined.
Stir in the chocolate chips.
Spoon half of the brownie mixture into your lined tin and spread it out evenly. Place the two Galaxy Caramel bars on top then cover with the rest of the brownie mixture.
Bake for around 30-35 minutes until the brownies have risen and are pulling away from the tin slightly. There should be a very slight wobble in the middle.
Leave them in the tin until cool then transfer them to the fridge overnight to set.
Once set, remove them from the tin, cut into squares and enjoy!