So what do you do when you've promised someone a Black Forest cake but can't seem to find sour cherries anywhere? I knew I would eventually encounter things which weren't widely available up here in Sweden, though I didn't think this would be it. I think we checked in two or three stores and there wasn't a can, jar, or pack of cherries in sight. None frozen, none in syrup, definitely no fresh ones at this time of year... yikes. Well, there goes that idea for a cake. Time to get creative. I co...