Glorious plums in the supermarket or fruit & veg shops always indicates, for me, the end of the stone fruit season. It was with heavy heart then last week, I purchased a small amount of unattractive speckled plums, thinking to do some cooking with them.  I was surprised to see my fella, hoeing into them when I got home and praising their flavour.  I bit into one, and wow!  Not only was it a dark deep red, it also tasted amazing. (I went back to the shop later that week and suggested that they cut them in half to attract customers - not sure if they've taken my advice yet.) Betty, on ABC Radio,  advised us that it was a blood plum.  Of course!  What else!
Several years ago a friend made me a cornmeal plum upside down cake.  I've looked for ages for the recipe and came across one at  Girl Detective (http://www.girldetective.net/?p=2578).  It's a bit pointless my repeating the recipe, and it's close and good - but still not quite there for me.  The only thing I would add, is that I use coarse yellow  cornmeal, and if you can get a variety of plums (blood etc), the cake looks beautiful.