Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan and line it with parchment paper, leaving some overhang for easy removal later.

In a medium saucepan over low heat, melt the chocolate chips and heavy cream together, stirring until smooth. Remove from heat and let cool slightly.

In a large mixing bowl, whisk together the eggs, granulated sugar, vanilla extract, and salt until well combined and slightly frothy.

Slowly pour the melted chocolate mixture into the egg mixture, whisking continuously until fully incorporated.

Sift in the cocoa powder and gently fold it into the batter until no lumps remain.

Pour the batter into the prepared loaf pan and smooth the top with a spatula.

Bake in the preheated oven for 30-35 minutes, or until the edges are set but the center is still slightly soft.

Remove from the oven and let the cake cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.

Once cooled, refrigerate the cake for at least 2 hours or overnight for best results.

Before serving, dust the top with powdered sugar and garnish with fresh berries if desired.