Cordial candies are round chocolate-covered candies filled with fruit preserves, such as cherries, and cream. These candies have a characteristic liquid center, which is made using an extraordinary ingredient called invertase.
Invertase is an enzyme known to break down sugar crystals. Achieving a fully melted center in a cordial can require up to a week of waiting for the process to occur. Other alternative processes are available for melting the sugary center, but using invertase is the easiest and most effective. Even when the candy is already covered with chocolate, the invertase inside still continues to melt the sugar until it is completely liquefied.