
In a large bowl, cream butter, 1/2 cup sugar and brown sugar until light and fluffy. Beat in egg, corn syrup, vanilla and flavoring. In another bowl, whisk remaining ingredients; gradually beat into creamed mixture. Refrigerate, covered, until firm enough to shape, about 1 hour.
Preheat oven to 375°. Place remaining sugar in a shallow bowl. Shape dough into 1-3/4-in. balls; roll in sugar. Place 2 in. apart on parchment-lined baking sheets.
Bake until edges are golden brown, 11-13 minutes. Remove from pans to wire racks to cool.