Pastille

(1) A small, hard, round or oval fruit sweet, often used as a lozenge.

(2) A disk of chocolate. The pastille has a unique shape that is intended to fit into the soft palate: its rounded top fits into the roof of the mouth, whilst its smooth flat base is designed so that the tongue can gently press the chocolate upwards. This means that the pastille fits, and melts, perfectly in the mouth.