Preheat oven to 175°C. Grease three 22cm round cake pans. Line bottoms with greaseproof paper; grease paper. Lightly dust with cocoa, tapping out excess.
Fill a 3,7-litre saucepan with water to a depth of 5cm. Heat to simmering. In a large heatproof bowl, combine chocolate, vanilla, salt, 1¼ cups granulated sugar and 10 tablespoons butter. Set bowl over simmering water. Gently stir occasionally until chocolate and butter melt. Remove from heat. While stirring, add egg yolks, 1 at a time, beating well after each addition. Gently fold in flour until just incorporated.
In another large bowl, with mixer on medium high speed, beat egg whites until frothy. Gradually add remaining ¼ cup granulated sugar and continue beating until stiff peaks form. Gently fold egg whites into chocolate mixture ⅓ at a time just until incorporated. Divide batteramong prepared pans.
Bake for 15 minutes or until cakes are set and toothpick inserted in centres comes out clean. Cool in pans on wire racks for 10 minutes. Invert onto racks; remove pans. Discard greaseproof paper; cool completely.
Place ½ cup raspberries in fine-mesh sieve set over small bowl. With wooden spoon, mash raspberries to extract 2 tablespoons juice; discard solids. In a large bowl, with mixer on medium speed, beat cream cheese and remaining butter until smooth and fluffy. Beat in icing sugar, then raspberry juice, until blended. If thin and runny, refrigerate for 5 minutes to achieve icing consistency. Transfer to a piping bag fitted with a 1cm plain tip.
Place 1 cake layer on cake stand. Decoratively pipe on ⅓ icing. Top with another cake layer. Repeat, piping remaining icing on final layer. Decorate top of cake with raspberries and serve with any remaining raspberries. Refrigerate for up to a day. Bring to room temperature before serving.