| 1 | Combine ?cup butter, egg yolks and vanilla extract in large bowl. |
| 2 | Beat at low speed with electric mixer until blended. |
| 3 | Set aside cocoa packet from mix. |
| 4 | Gradually add cake mix. |
| 5 | Blend well. |
| 6 | Divide dough in half. |
| 7 | Add cocoa packet and remaining 1 tablespoon butter to half the dough. |
| 8 | Knead until well blended and chocolate colored. |
| 9 | Roll out yellow dough between two pieces of waxed paper into a 6" square. |
| 10 | Repeat with chocolate dough. |
| 11 | Remove top pieces of waxed paper from yellow and chocolate doughs. |
| 12 | Cut each square into twelve ? wide strips. |
| 13 | To assemble, place one strip chocolate dough on plastic wrap. |
| 14 | Brush edge with beaten egg. |
| 15 | Place one strip yellow dough next to chocolate dough. |
| 16 | Brush edge with egg. |
| 17 | Repeat with a second chocolate strip, egg and a second yellow strip to make first row. |
| 18 | Brush top of row with egg. |
| 19 | Prepare second row by stacking strips on first row, alternating yellow over chocolate strips. |
| 20 | Brush edge and top of each strip with egg. |
| 21 | Repeat for third row to complete one checkerboard bar. |
| 22 | Repeat with remaining strips to make second bar. |
| 23 | Cover with plastic wrap. |
| 24 | Refrigerate 1 hour or until firm enough to slice. |
| 25 | Preheat oven to 350°F. |
| 26 | Grease baking sheets. |
| 27 | Cut checkerboard bars into ? slices. |
| 28 | Place 2" apart on greased baking sheets. |
| 29 | Bake at 350°F. |
| 30 | For 7-9 minutes or until edges are light golden brown. |
| 31 | Cool 1 minute on baking sheets. |
| 32 | Remove to cooling racks. |
| 33 | Cool completely. |
| 34 | Store in airtight containers. |
| 35 | makes 4 dozen cookies. |
