Preheat the oven to 180c/350f and line a baking tray that's approx. 20cmx30cm and 3cm deep with baking parchment. Leave a little of the parchment overhanging the tray to make it easier to get the brownie out later.
Melt the dark chocolate and butter together in a bowl over a pan of simmering water (make sure the bowl isn't touching the water though). Or alternatively melt the chocolate in the microwave in 30 second increments, giving it a stir each 30 seconds. Then add the butter for the last 30 seconds to melt. Stir and leave to cool slightly.
Whisk the eggs and sugar on medium until thick and creamy in a large bowl using a mixer or hand whisk.
Slowly whisk again, and pour the melted chocolate butter in. Pour it at the side of the bowl in a thin stream, whisking all the time, so that the eggs don't scramble with the warm chocolate.
When the chocolate is thoroughly mixed in, sieve the flour, cocoa powder and baking powder over the mixture, and then add the ground almonds. Fold into the mix gently, in a figure of eight. This will help to keep the air in.
Pour the mixture into your baking tray, and use a palette knife to ensure it goes all the way to the edges.
Arrange the chocolates on top of the brownie mix evenly, so there is 1 piece per portion of brownie. Push the caramel into the mixture slightly and place the tray in the oven.
Cook for 25 minutes.
Take out of the oven and leave to cool in the tray. Lift the brownie out of the tray using the baking parchment and place on a chopping board. Use a sharp knife to slice the brownie into portions. It will crumble slightly when you cut it, but it crumbles less, the longer you leave it to cool.