Step 1: Preheat your oven to 350°F (175°C) and grease a 9×9 inch baking pan or line it with parchment paper for easy removal.
Step 2: In a large bowl, combine the melted butter, granulated sugar, and brown sugar. Whisk by hand until well combined.
Step 3: Add the eggs one at a time, whisking well after each addition. Stir in the vanilla extract.
Step 4: Sift in the cocoa powder, flour, and salt. Gently fold the dry ingredients into the wet ingredients using a spatula until just combined.
Step 5: Fold in the dark chocolate chips and pour the batter into the prepared baking pan, smoothing the top with a spatula.
Step 6: Bake for 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs attached.
Step 7: Allow the brownies to cool in the pan for at least 20 minutes. While cooling, use a straw or small piping tip to poke two ‘bite’ holes into each square area (total of 32 holes for 16 brownies).
Step 8: Fill a small squeeze bottle with the raspberry jam (mixed with a drop of red food coloring if desired) and carefully pipe the jam into each hole until it just overflows slightly.