1Melt chocolate chips over heat and let cool. Combine flour, baking soda and salt. Set aside. With an electric mixer set at medium-low speed, beat butter and sugar until fluffy. Add vanilla, corn syrup and egg and continue beating until well combined. Reduce mixer speed to low and beat in melted chocolate. Add flour mixture and continue beating until well combined.
2Refrigerate until firm, about 30 minutes.
3Shape dough into approximately 1 inch balls and roll in additional sugar. Put on ungreased baking sheets about 1 inch apart. Bake at 350 degrees F (175 degrees C) until edges are lightly browned, 10 to 15 minutes. Let stand on baking sheets 1 minute before removing to wire racks to cool.