The jagged pattern imprinted on these cookies is achieved by pressing the serrated end of a cake comb into the dough. This metal or plastic tool is designed to make a pattern in cake frosting.
Add 1 or 2 drops of food coloring to the dough and knead just until the color is completely distributed. On a lightly floured work surface, using a floured rolling pin, roll the dough to about ¼ inch (6 mm) thick. Using a ruler as a straightedge and a pizza wheel or sharp knife, cut triangles of various sizes. Use a me