Tuscany, specifically the wine-growing zones around Florence, Siena, and the Chianti classico area. The schiacciata all'uva is specific to the 2-3 weeks of the vendemmia in September-October — it is a deeply seasonal dish that has no out-of-season version.
Schiacciata all'uva is the Tuscan autumn flatbread made during the vendemmia (grape harvest) with Sangiovese wine grapes pressed into a simple olive-oil dough sweetened with sugar and flavoured with rosemary. The grapes are both inside the dough and pressed onto the top before baking — the heat bursts them, their juice caramelises into the dough, and the seeds and skins create a texture and bitterness that balances the sweetness. It is eaten warm from the oven throughout the harvest weeks and nowhere else in the year.
The caramelised grape juice, the olive-oil bread, the sugar, and the rosemary create a flavour that is simultaneously bread, pastry, and wine — all the elements of Tuscan culture in a single bite. The tannin from the wine grape skins provides a bitter note that prevents the sweetness from becoming cloying. It smells of the harvest.
The dough is a basic focaccia dough with sugar added: flour, water, yeast, olive oil, salt, and sugar. Roll or press two thin layers; press half the grapes into the lower layer, place the upper layer on top, press more grapes on top. Sprinkle generously with sugar and fresh rosemary leaves. Bake at 200°C until the top is golden and the grape juices have caramelised and darkened around each burst grape. The combination of the dough's bread flavour, the grape's fermented-sweet juice, and the rosemary's resinous note is specific to this single dish.
The interior layer of grapes steams inside the dough and creates pockets of grape juice that burst when bitten. This is the characteristic pleasure of the dish — the alternation between bread and juice. Eat the day it is made — the grape juice makes the bread stale quickly. Seek out the black variant (uva nera) over white grapes — the tannins from the red grape skins add complexity.
Using table grapes — they are too large and too sweet; use small wine grapes (Sangiovese, Canaiolo) with their natural tartness and tannin. Not pressing the grapes far enough into the dough — they should be embedded, not just sitting on the surface. Under-baking — the grape juice needs to caramelize and concentrate; a pale schiacciata is underseasoned.
Pellegrino Artusi, La Scienza in Cucina; Marcella Hazan, Marcella's Italian Kitchen