Yema is a custard candy that we Filipinos inherited during the Spanish era.

“Yema” is actually a Spanish word that means “yolk.” During the Spanish colonial period, egg whites & egg shells were used to build churches in the Philippines. It was a technique that uses them as mortar to hold the stones together. And that left an overabundance of egg yolks. Since we Filipinos are accustomed to not letting food fall into waste, Pinoy ingenuity and passion for food came to the fore, it gave birth to recipes that are mainly based on yolks, like leche flan, yema & more.

Source: http://www.choosephilippines.com/eat/recipes/1625/yema-filipino-dessert/img-4890