Preheat oven to 350ºF. Using an electric mixer, beat butter or margarine and sugar together in a medium mixing bowl until light and fluffy. Add eggs, mixing well. Combine oats, flour, baking soda and salt in a separate mixing bowl. Add to butter mixture in several additions, mixing well after each addition. Stir in dried cranberries. Drop by rounded teaspoonfuls onto ungreased cookie sheets. Bake for 10-12 minutes or until golden brown. Remove from oven. Immediately press a mint chocolate candy into the center of each cookie. Cool on wire rack. Makes approximately 2 1/2 dozen cookies.