Plum Squares

In late summer and early fall, when the blue-purple prune plums are in season, almost every coffeehouse will have plum cake sitting front and center in the display case. This version is based on the one served at Cafe Sperl, one of Vienna’s protected landmark coffeehouses. With its easy-to-make short crust dough, it can be prepared in no time and disappears as quickly as homebaked apple pie in an American diner in October.