Preheat oven to 350 degrees.
Grease an 8 x 8 metal pan and line with parchment paper. Set aside.
Chop dark chocolate bar then melt with butter in a large microwave-safe bowl in 30 second increments.
Add sugar to bowl and whisk vigorously.
Set aside to cool for 10 minutes.
Add eggs, one at a time, whisking vigorously for one minute.
Add vanilla then stir until evenly distributed. Set aside.
In a separate bowl, sift together flour, cocoa powder and salt.
Add dry ingredients to wet, stirring with a spoon until just combined. Avoid overmixing.
Gently fold in 1/2 cup of raspberries and 1/4 cup of dark chocolate chips.
Pour batter into baking pan. Smooth top to even.
Top batter with remaining dark chocolate chips and raspberries.
Bake for 25 to 30 minutes or until the tip of a toothpick inserted into the center of brownies comes out with a few bits of moist crumbs attached. Do not overbake.
Cool completely before cutting.
Garnish with fresh raspberries, if desired.
Store in an airtight container at room temperature for 2 days or in the refrigerator for up to 5 days.