raspberry chocolate brownies

There is something about the combination of these two ingredients that is perfect. So in taking a step further towards my ultimate goal of the perfect chocolate brownie I embarked on this one of James Martin: 250g unsalted butter, 350g dark chocolate melted together and left to cool slightly.  In separate bowl whisk 3 eggs together until thick and gradually add in 250g soft brown sugar until mixture smooth and shiny, then add the warm chocolate mixture.  Fold in 110g flour, 1 tsp baking powder and a pinch of salt.  Pour half the mixture into a 23cm baking tin lined with parchment, place 175g fresh raspberries (I used frozen ones from our summer garden so they were slightly mushy) on top - then the remainder of mixture.  Bake at 170C for aprox 40 minutes, a skewer should come out with a little mixture attached. Unfortunately I slightly overcooked mine as it came out clean alas.  Left to cool then cut into 9 squares and sprinkled with icing sugar.  Verdict.  Edible but not perfect!  A bit too cocoay maybe I need to change the chocolate?  Used 70%.  Top slightly crunchy but lacks the chewiness of the perfect brownie.