Chocolate-Marzipan Pinwheels

Butter cookie dough: Cream butter, sugar and salt. Add egg yolks and vanilla - beat until smooth. Add flour gradually, mixing until incorporated. Chocolate dough: Measure out 1 cup of dough. Beat dough, marzipan, cocoa powder, almond extract and egg whites until smooth. Divide both butter cookie and chocolate dough into 2 equal portions. Roll each piece of dough between sheets of wax paper into a 10x15 inch rectangle. Place a rectangle of chocolate dough on top of a rectangle of butter cookie dough and roll from long side to form pinwheel. Chill at least 2 hours. Slice into 1/4 inch thick rounds and bake at 350 degrees for 12-15 minutes.