Preheat the oven to 350 degrees F. Line a 9x13-inch baking pan with foil or parchment paper, spray with cooking spray, and set aside.
In a medium-sized bowl, whisk together the flour, cocoa powder, and salt. Set aside.
In another medium-sized bowl, whisk the melted butter, sugar, and vanilla extract together. Add the eggs, one at a time, whisking until each egg is well combined before adding another.
Switch to a spatula, and in a couple of additions, add the dry ingredients to the wet. Once things are just combined, add 1 cup of frozen raspberries and ½ cup each of both kinds of chocolate chips. Stir until they are well distributed.
Spread the brownie batter in an even layer into the bottom of the prepared baking pan. Sprinkle the remaining ¼ cups of berries and chocolate chips on top.
Bake for 28-33 minutes, or until a toothpick, when inserted into the center, comes out clean.
Allow the brownies to cool completely before slicing.