Preheat the oven to 350° F and line an 8x8 baking pan with parchment paper, leaving a 1” overhang for easy removal; set aside.
Add the butter and semi sweet chocolate chips to a saucepan and heat over medium low, whisking until the butter and chocolate have melted; remove from the heat.
In a large bowl, whisk the eggs, sugar and brown sugar together for 45 seconds. Then, add the melted chocolate, along with the vanilla, to the bowl and whisk to combine.
In a separate bowl, stir the flour, cocoa powder, and salt together. Pour the dry ingredients into the wet and gently fold together. Do not overmix! Last, fold in the chopped chocolate and most of the raspberries, reserving a few to sprinkle on top. It’s ok if some of the raspberries break while folding, but try to stir gently so some of them stay intact.
Transfer the batter to the prepared pan, using a spatula or spoon to smooth out the top. Then, add the reserved raspberries on top, pressing them into the batter.
Place the pan in the oven and bake the brownies for 35-40 minutes. Let the brownies cool in the pan for 1-2 hours before pulling on the parchment tabs to remove them. Slice into 9 (or 16) brownies and enjoy!