Heat oven to 350 degrees. In large, microwavable bowl, heat chocolate and butter on high 1-2 minutes, or until butter is melted. Let stand 10 minutes to cool slightly.
Add 1/2 cup sugar, egg and peppermint extract. Beat with electric mixer on medium speed until well-blended. Gradually beat in flour on low speed until well-mixed.
Shape dough into 1-inch balls. Press chocolate candy into center of each ball, forming dough around candy to enclose it. Roll in remaining sugar to coat. Place 1 inch apart on greased baking sheets.
Bake 9-11 minutes, or until cookies are set. Cool on baking sheets 5 minutes. Remove to wire racks; cool completely.