Is it necessary to reduce the vanilla content in the cake (eg Rose’s white choc whisper cake) when using green & blacks white chocolate given that it already has some vanilla in it?

It’s normal for white chocolate to contain vanilla along with cocoa butter, milk solids, sugar and lecithin. The only difference with Green and Black’s is that it contains the little seeds of the vanilla bean, not just extract.

In any case, the only reason I can think of to decrease the vanilla in the cake is if you’re not fond of the taste and want to keep it to a minimum.

Great! Thank you - I just didn’t want to get carried away thanks for your help!