Chocolate to vanilla extract ratio for chocolatey drinks?

Some may remember a thread from a few months back in which I asked about making a homemade Irish cream. Due to uncertainties particularly about how to keep it fresh for a few months of storage, I abandoned the idea. However, I still had a fermenting spirit base kit which is now around 17-20% (had to measure with a very inaccurate hydrometer this time so that's a ballpark), clear, filtered using the usual charcoal -> kieselsol -> chitosan regime and about to be siphoned away from the sediment for flavouring. Tastes good enough as it is, basically just like watered down vodka. Exactly what one would expect.

Still wanting to make something in the Christmas spirit (EDIT: Pun entirely unintentional ), I hit on the idea of simply making a chocolate and vanilla liqueur. To that end, I have a jar of cacao nibs floating in around 100ml of glycerine and 100ml of boiled water, which has been there for just over a month. I also have several bottles of vanilla extract from Tesco.

So for those who've made anything using a cacao tincture / vanilla extract mix, what kind of ratio should I be going for? I intend to pour the entire 200ml cacao tincture in simply because previous experience making a Malibu Coconut Rum clone this summer denotes that 100ml of glycerine is vital for mouthfeel, I was very happy with how that turned out. I'm told, however, that vanilla extract is exceptionally strong tasting, and a few people I know who've used it in baking have advised that the ratio will probably involve a lot less vanilla in proportion to whatever amount of cacao ends up in the final product.

Anyone have any experience using these two ingredients in the same brew together, whatever it may be? And if so, what kind of ratio should I go for?