Preheat your oven to 350°F. Line an 8x8-inch square baking pan with parchment paper leaving a 2-inch overhang at each side and secure the sides down on the edge of the pan with ¾-inch binder clips.

First freeze the raspberries. Place them on a tray lined with waxed paper or parchment paper and freeze for 30 minutes until hardened.

Make the brownie batter. In a medium heatproof bowl set over a pot with ½-inch of barely simmering water, stir together dark chocolate, butter and salt using a spatula until completely melted, smooth and glossy. You can also melt it in the microwave in short 20 seconds bursts with frequent stirring.

Combine eggs and sugar in a large bowl and whisk vigorously until pale and thick. This will take about 1 minute. Add warm chocolate mixture, vanilla and salt and whisk until evenly combined. Add cocoa and whisk it in.

Using a rubber spatula, gently stir in flour until well incorporated and batter is smooth. Fold in white chocolate chunks and flash-frozen raspberries. Scrape batter into prepared pan and spread it out gently into the corners then top with a few more fresh raspberries.

Bake for 30-35 minutes until the topis shiny and a cake tester inserted into the center of the brownies comes out with a few moist and sticky bits. About 15 minutes into baking, sneak in and quickly pop a few white chocolate chunks on top. I do this a little later into the baking time since white chocolate has a tendency to burn if exposed to dry heat. If you don’t freeze the raspberries then it will take closer to 25 minutes to bake.

Transfer pan to a wire rack and let cool completely, then refrigerate for 1 hour before slicing and enjoy!