How to make the perfect German plum cake

Should this traditional dessert have a dough or pastry base - and which variety of fruit works best?For a place with such lovely plums (complaints to the editor, please), we have a serious dearth of recipes for the glorious annual glut. Crumble, jam and pie just about covers it, as far as I can tell (though all corrections welcome), none of which, delicious as they are, come close to the national institution that is the German plum cake, variously known as zwetschgendatschi, zwetschgenkuchen, qu