Preheat the oven to 350°F (175°C). Grease a 9×13 inch baking pan.
In a large bowl, cream together the softened butter, granulated sugar, and brown sugar until smooth.
Beat in the eggs one at a time, then stir in the vanilla extract.
In a separate bowl, whisk together the flour, cocoa powder, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the dark chocolate chips and fresh raspberries gently to avoid breaking the berries.
Pour the batter into the prepared baking pan and spread it evenly.
Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Remove from the oven and let it cool in the pan for about 10 minutes, then transfer to a wire rack to cool completely.
Once cooled, dust with powdered sugar, cut into bars, and serve.