The Turkish spice made from dried wild cherry pits and used in pastries is mahlep.
Mahlep, also spelled mahaleb or mahlepi, is produced from the seed kernels inside the stones of the Mahaleb or St Lucie cherry, Prunus mahaleb. The stones are cracked open, the small kernels are removed, and those kernels are ground into a fragrant powder.
Its flavor is often compared with bitter almond, cherry and marzipan. Because it is intense, mahlep is normally used in small quantities to perfume sweet dough rather than dominate it. In Turkey it is especially associated with poğaça and other savory or lightly sweet pastries. It also appears in regional breads and festive baked goods across the Middle East and eastern Mediterranean.
Mahlep has a long culinary history. References to using the fruit or seed of a related “ḫalub” appear in ancient Sumerian traditions, while later Greek, Armenian and Arabic cuisines developed their own pastry uses. Isot is a pepper, sumak is a tart berry spice, and çörek otu is nigella seed, so none is the cherry-derived seasoning described here.