Hello - I am going to be filling a WASC with the raspberry filling found on here :
http://cakecentral.com/recipes/raspberry-filling/

I would like to fill and let the cake settle overnight, but i am not sure if it would have be put in the fridge of if i could leave it out on the counter.

I am filling the cake thurs evening, cake will be covered in MMF friday and served fri evening.

Personally, I wouldn't. It's got fresh fruit in it. How about using raspberry jam instead?

It will be fine. I've left fillings like this out overnight in a cake with no problems. Fresh fruit will generally not spoil overnight at room temperature and all of the other ingredients are fine at room temperature. There is no dairy or something similar to worry about. I wouldn't worry about it at all.

Since the fruit is strained out from the recipe and only the liquid is used, i wasnt sure if perishable or not.