You may refer to the category known as Vaniglia loquats, they are a local race of several cultivar which is grown in the island of sicily. They differ from standard loquat because of the lesser acidity and also are more tasty. Also, they are almost impossible to find for sale because the fruit is very easily damaged, and skin should be a little paler, so either you live in sicily and own a plant, or you won't find them on the market. I managed to get a plant just recently.
Even here this kind of loquat is pretty rare.