St. Martin of Tours (397), was born in Pannonia (modern Hungary) of pagan parents around the year 316. Having become a soldier at age fifteen, he later gave up military life and was baptized. Sooon after he founded a monastery at Liguge in France, where he led a monastic life under the direction of St. Hilary. He was ordained a priest and chosen bishop of Tours. He provided an example of the ideal good pastor, founding other monasteries, educating the clergy, and preaching the Gospel to the poor. He is the patron of soldiers and the uncle of Ireland's St. Patrick.
In Poland, rich cookies are shaped like horseshoes to remember St. Martin's snow-white horse, on which he "comes riding through the snow" when one least expects him.
From The Catholic Parent Book of Feasts by Michaelann Martin
St. Martin horseshoe cookie recipe can be found at Heart of the Kitchen.