I do this every fall. I start checking the local markets for Italian prune plums so I can make one of my favorite desserts, the Plum Pie (Zwetschgenkuchen) from Joan Nathan’s Jewish Cooking in America.
The most reliable source for these plums is ShopRite, other markets may or may not have them. Regular plums don’t cook the same, I tried that once, and was not pleased with the result, as they didn’t “melt down” the way the prune plums do. I think this year I bought the very last plums they had at ShopRite, just enough to make the pie (which is really more like a tart), in mid/late September.
I even had a little crème fraîche in the fridge, which was the perfect accompaniment, although, in truth, it is gilding the lily.