1In heavy small saucepan over low heat, heat chocolate chips, stirring occasionally, until melted and smooth.
2Pour melted chocolate into bowl and add flour, butter, corn syrup, baking soda, salt, egg and 1/2 cup sugar. Mix with electric mixer at low speed until blended. Increase speed to medium; beat until well mixed, scraping bowl frequently with rubber spatula.
3Wrap dough with plastic wrap and refrigerate until easy to handle, about 2 hours.
4Preheat oven to 350 degrees F (180 degrees C).
5Measure 1/3 cup sugar into small bowl. Shape dough into 96 balls; roll balls in sugar to coat. Place in even number of balls, about 2 inches apart, on ungreased large cookie sheet.
6Bake cookies 12 to 15 minutes until set. Immediately remove half of cookies from cookie sheet and invert onto work surface. While still hot, place chocolate-covered mint patties on remaining cookies, top side up. Press cookies together slightly so mint patty spreads out to cookie edges as it melts. With pancake turner, remove cookies to wire racks to cool. Repeat with remaining dough and mints.