Grease a pie pan and dust with the cocoa powder.
In a microwave, combine the chocolate and butter.
In a large bowl, using an electric mixer fitted with the whisk attachment, beat together the egg yolks, 6 tablespoons of the granulated sugar, the espresso, vanilla and salt on medium-high speed until pale and very thick, about 3 to 5 minutes. Gradually pour in the chocolate mixture and continue beating until well blended.
In a separate bowl beat the egg whites on medium-high speed until foamy, about 1 minute. Gradually add the remaining 3 tablespoons granulated sugar and continue to beat until medium-firm peaks form, about 2 minutes. Scoop half of the egg whites onto the chocolate mixture and fold them in gently. Fold in the remaining whites just until no streaks remain.
Pour the batter into the prepared pan and spread it out evenly. Bake in a 300F oven until the torte puffs slightly and a toothpick inserted into the center comes out very moist but not liquid, about 38-40 minutes. Transfer the pan to a wire rack and let cool for 30 minutes.
Let the torte cool completely, then cover and refrigerate until very cold, at least 4 hours or up to overnight.
Garnish the torte with the raspberries and dust with confectioners’ sugar.