ANo judgement. But I want to use a box cake mix for this.

Has anyone got a recipe for a Black Forest cake using a box mix? I have never made Black Forest before. What is kirsch? Also, how many days in advance should this be made prior to delivery?

Any advice on this cake would be much appreciated thanks! :)

Check out this link....and Kirsch is a cherry brandy

http://southernfood.about.com/od/chocolatecakes/r/blbb541.htm

I would make it a couple days before delivery

To me black forest is chocolate cake, fresh cream and black cherries in a sweet goey type sauce ideally with kirsh (cherry liquor) drizzled over the baked layers of the cake or mixed into the cherry sauce.

I don’t see why you couldn’t just use your favourite chocolate cake box mix. In the UK there is a black cherry pie filling which comes in a tin and is ideal (and SO yummy!!).

I would make it a minimal amount of days before delivery because of the cream.

Sure you can use a box mix.  Traditionally, a Black Forest cake is a chocolate genoise soaked in kirschwasser and filled with fresh cherries and whipped cream, then iced with whipped cream and dusted with chocolate shavings.  The whole thing is supposed to be very light.  If you want something heavier you can use the WASC.  I would do it no more than a day in advance due to the whipped cream.  You don't want it breaking down on you.  You can get a cheap bottle of kirsch at the liquor store.  All I can get here is bottom shelf, so I bought real cherry extract from Olive Nation (NOT artificial McCormick!).  You can reduce the cheap kirsch on the stove to concentrate the flavor (the cheap stuff is not the most flavorful).  It will mellow out anyway in 24 hours if you brush it directly on the cake. 

I personally wouldn't use cherry pie filling but I know a lot of Americans like it that way.  It tends to be a bit sweeter.  If you wanted to go the pie filling route, I would make your own with canned cherries.  I think the canned pie filling is to "tinny" tasting.