Melted butter, to grease, plus extra 500g butter, chopped
500g white chocolate, chopped
3 cups caster sugar
4 free-range eggs, lightly beaten
250ml sour cream
2 tsp vanilla essence
3½ cups plain flour
2 cups self-raising flour
1 cup frozen raspberries
Pink icing colour gel and violet icing colour gel, to decorate
White chocolate frosting
250g butter, chopped, softened
2 cups icing sugar mixture
250g white chocolate, melted
2 Tbsp raspberry jam
Preheat oven to 150 degrees C fan-forced (170 degrees C conventional). Grease two 20cm round cake tins with butter and line bases and sides with baking paper.
Combine chocolate, water and extra butter in a large saucepan and stir over low heat until smooth. Don't boil. Transfer to a large bowl and set aside to cool to room temperature.
Add sugar, eggs, sour cream and vanilla to cooled chocolate mixture and whisk until combined. Sift in flours, then stir until just combined. Add raspberries and swirl through batter. Spoon half the batter into a bowl, cover with plastic wrap and set aside at room temperature.
Pour remaining mixture evenly between prepared tins. Bake for 50 minutes, or until cooked when tested with a skewer. Cool cakes in tins for 15 minutes before turning out onto a wire rack to cool completely.
Regrease and line tins and then repeat Step 4.
Meanwhile, for frosting, put butter and icing sugar in a large bowl. Beat with an electric hand mixer until soft and fluffy. With motor running, gradually add melted chocolate in a slow, steady stream. Continue to beat until pale, fluffy and very smooth. Put 1¼ cups of frosting in separate bowl, add jam and swirl through.
To assemble cake, trim tops of cooled cakes to level using a cake leveller or serrated knife.
Put one cake layer on a serving plate, cut side up. Spread with 1/3 of the jam-flavoured frosting. Repeat layering with cake and jam frosting until all cake layers have been used, finishing with a layer of cake.
Put a tablespoon of remaining frosting into 2 separate bowls. Tint one with a little pink gel until pale pink, and the other with a little violet gel and a little pink gel until pale lilac in colour. Set aside.
Using a small palette knife, spread remaining frosting over the top and side of the cake to cover completely.
Put small dots of pink and lilac coloured frosting sporadically around the side of the cake.
Using a large palette knife to drag coloured frosting around cake to create a soft wash effect.
Decorate cake with paper craft flowers.
After another white chocolate cake recipe? Watch the video below.