Membrillo, or quince paste, is a sweet, spreadable paste made of the flesh of the quince. Confusingly, it is sometimes called quince cheese, but it contains no dairy, and is more like a thick jelly.
It is used in sweets, such as cookies and cakes, and is often paired with cheese, especially Manchego; in the Iberian peninsula and Latin America, this pairing is called queso y dulce. In Argentina, Costa Rica, and Uruguay, it is used in pastries.