Step 1

Combine flour, baking powder and salt. Beat butter and granulated sugar in large bowl with mixer until light and fluffy. Add egg, chocolate and vanilla; mix well. Gradually add flour mixture, mixing well after each addition.

Step 2

Divide dough into 4 equal portions; roll each into 5-inch-long rope. Roll, 1 at a time, in powdered sugar until evenly coated on all sides. Wrap individually in waxed paper. Refrigerate 2 hours or until firm.

Step 3

Heat oven to 350ºF. Cut each log into 16 slices. Place, 2 inches apart, on parchment-covered baking sheets.

Step 4

Bake 8 to 10 min. or just until tops are firm to the touch. Cool 1 min. on baking sheets. Remove to wire racks; cool completely.