Using tofu in place of additional chocolate gives this cake a deliciously fudgy texture.
Preheat oven to 160°C. Spray a round 20cm cake pan with vegetable oil. Line base and sides with non-stick baking paper.
Process tofu, sugar, egg yolks and vanilla in a food processor until smooth. Add chocolate and process until smooth. Transfer to a bowl. Fold in combined flour.
Beat eggwhites with an electric beater in a clean, dry bowl until soft peaks form. Fold one-third of the eggwhite into chocolate mixture with a large metal spoon until just combined. Repeat, in two more batches, with remaining eggwhite. Spoon cake mixture into prepared pan and smooth surface. Bake for 40-45 minutes or until a skewer inserted into the centre comes out clean. Set aside in pan to cool.
Cut cake into slices. Top with yoghurt and raspberries and dust with cocoa powder to serve.