1 1/2 pounds prune plums or other ripe stone fruit
1 lemon finely zested
2 tablespoons apricot jam
2 tablespoons butter cut in pieces
1/2 cup fine dry bread crumbs
2 tablespoons zucchero di canna or white sugar
1/4 teaspoon powdered cinnamon
Whipped cream or vanilla ice cream
Put the flour, sugar and salt in the bowl of a food processor fitted with the metal blade and process for a few seconds to mix the dry ingredients.
Cut the butter into 1/2-inch pieces, drop them onto the flour, and pulse the machine 10 or 12 times, in short bursts, 20 seconds in all. The mixture should be crumbly with only a few larger bits of butter visible.
Sprinkle 3 tablespoons of water on top of the dough-immediately pulse about 6 times, only a second or two each time. You want the crumbs to gather together in wet clusters, a bit like cottage cheese curds-don’t expect a mass of dough to form. If they haven’t gathered, sprinkle on more water, a teaspoon at a time, and pulse 2 or 3 times after each.
When the clusters form, scrape them all out of the bowl, press them together and knead just for a few seconds to form smooth, tight dough. Flatten it into a disk, wrap well in plastic wrap and refrigerate for 3 hours or up to a day before using.
Arrange a rack in the middle of the oven with a baking stone. Preheat the oven to 375 degrees.
Rinse the plums and pat dry. Cut them in halves, and remove the pits. Toss the halves with the lemon zest, apricot jam and butter bits in a mixing bowl. (If using larger stone plums fruits like peaches or nectarines, cut them in quarters or wedges.)
Toss the bread crumbs, sugar and cinnamon together.
On a lightly floured board, stretch the dough into a circle, rolling from the center in all directions. Turn the dough over as it stretches and flour the work surface as needed. Roll the circle of dough to a diameter of 15-inches and lay it, centered, on parchment. Trim the outside edges of the dough, with a sharp knife or scissors, cutting away ragged or thin spots, keep a minimum 13-inches diameter. Lift the parchment with the dough on it to the baking sheet.
Sprinkle about 1/3 cup of the bread crumb mix in a 7 to 9-inch diameter circle in the center of the dough, as a base for the fruit. Use more crumbs to form a thicker layer for juicier fruit; if using a drier fruit, use less crumbs. Arrange the coated plum halves, cut side up, on top of the crumb base.
When you’ve assembled your fruit in the middle of the dough, you’ll fold the uncovered band of pastry on top of the fruit. The width of the band will vary with your arrangement of the plums, but you should have at least 2-1/2 inches of dough. Finally, sprinkle 1 or more tablespoons of sugared bread crumbs over the visible fruit in the center. As before, use more crumbs on juicy fruit. If you have any left over, sprinkle them over the pleated dough.
Put the baking sheet with the crostata into the oven, on the stone and bake for 25 minutes; rotate the pan back to front for even cooking. Check the browning of the crust after 40 minutes: it should be light gold. If too dark, lay a piece of foil on top. Bake for another 15 minutes or more until the fruit is bubbling and has caramelized on the edges.
Let cool on the baking sheet for about 15 minutes before lifting it, with the parchment, to a wire rack to continue cooling. When set, slide it off the parchment, onto a platter.
Serve warm or at room temperature, cut in wedges, with whip cream or vanilla if you wish.