Start by gently melting the white chocolate in a microwave. Once it is all melted, set aside to cool.
Soften the butter in the microwave. Add this into a mixing bowl along with the caster sugar. Mix well, until light and fluffy.
Next, add in two eggs and mix again until combined. Then crack in the remaining eggs and the oil and mix again.
Zest and juice the orange. Add this into the bowl and whisk it all together.
Now, add in the flour. Mix this until just combined through.
Pour in the dried cranberries and melted white chocolate.
Mix again until you have a smooth cake batter.
Evenly spread the batter into 2 x 6 inch round cake tins, lined with baking paper. Cook at 160 fan for 40 minutes or until a skewer comes out clean.
To make the buttercream, soften the butter in the microwave. Use a food mixer to mix the butter on a high speed for 3-4 minutes. Next add in the icing sugar, whole milk and vanilla extract and mix again for 3-4 minutes until combined and smooth. Lastly mix through some melted white chocolate. Yum.
Layer up your cake with the white chocolate buttercream. Sprinkle some chopped fresh cranberries onto each layer. Finish off with some piping, cranberries and rosemary sprigs.