1/2 c. shortening
1/3 c. plus 1 tbsp. butter
2 egg yolks
1/2 tsp. vanilla
1 pkg. fudge marble cake mix

Combine shortening, 1/3 cup butter, egg yolks and vanilla; mix at low speed. Set aside cocoa packet. Gradually add cake mix. Blend well. Divide dough. Add cocoa packet and remaining 1 tablespoon butter to half the dough. Knead until well blended.

Roll out dough between 2 pieces of waxed paper. Repeat for chocolate dough. Lay yellow dough directly on top of chocolate, rolling jelly roll fashion beginning at wide side. Refrigerate 2 hours. Preheat oven to 350 degrees. Grease baking sheets. Cut dough into 1/8 inch slices. Bake at 350 degrees for 9 to 11 minutes until lightly browned.