Step 1

Preheat oven to 180°C. Line a baking tray with baking paper. Stack two 7.5cm egg rings on tray. Repeat with 6 more rings to make 4 stacks. Cut four 7.5 x 32cm strips of baking paper. Spray with oil. Line stacks with the strips.

Step 2

Use an electric beater to beat the butter, sugar and vanilla in a bowl until pale and creamy. Beat in the chocolate until smooth. Add the egg. Beat until combined. Fold in flour alternately with buttermilk. Spoon among stacks and smooth surfaces. Bake for 20 minutes or until a skewer inserted into centres comes out clean. Set aside on the tray on a wire rack to cool completely.

Step 3

Remove egg rings. Cut each cake horizontally into 3 layers. Whisk the cream in a bowl until soft peaks form. Mash raspberries and jam in a bowl.

Step 4

Divide the cake bases, cut-side up, among serving plates. Top with a dollop of cream and a spoonful of the raspberry mixture. Continue layering with remaining cake, cream and raspberry mixture, finishing with cake. Decorate with extra raspberries and dust with icing sugar.