1. Beat butter, sugar and vanilla in large bowl on medium speed of mixer until fluffy. Add eggs; beat well. Beat in corn syrup.
2. Combine flour, cocoa, baking soda and salt; gradually add to butter mixture, beating until well blended. Cover; refrigerate until dough is firm enough to handle.
3. Heat oven to 350°F. Shape dough into X and O shapes. Place on ungreased cookie sheet.
4. Bake 5 minutes or until set. Remove from cookie sheet to wire rack. Cool completely. Decorate as desired with icing. Makes about 5 dozen cookies.
To shape X's: Shape rounded teaspoons of dough into 3-inch logs. Place 1 log on cookie sheet; press lightly in center. Place another 3-inch log on top of first one, forming X shape.
To shape O's: Shape rounded teaspoons of dough into 5-inch logs. Connect ends, pressing lightly, forming O shape.