Since it is now the holiday season, I thought we could spend this weekend making some baked goods that have mathematical patterns on them. In this post, we'll look at making cookies that have a fractal pattern based off of a modification of the pixel cookie technique. The people at Evil Mad Scientist Laboratories wrote a blog entry a couple of years ago on making fractal cookies based off of the Sierpinski Carpet. They used chocolate dough to make the "holes" in the design. They've also posted an entry on how to make fractals using clay with the same technique. Here the results are much more precise. On Sunday, I decided to follow their recipe for making fractal cookies, but I used red paste food coloring to color the dough for the holes.

Materials and Tools Cookie dough (I followed a recipe similar to the one used by the Evil Mad Scientists)

Food coloring (The Evil Mad Scientists used chocolate)

Baking sheet

Parchment paper

Sharp knife

Oven

Making the Fractal Cookies Roll out eight logs and use your hands and a working surface to form them into square prisms. Use a sharp knife to trim the edges. The ones I formed were about 3 inches long. Form a few logs of your alternate color. You will need as many of these as you are making iterations. Surround the alternate colored log and squeeze the pieces together. A tiny bit of water could help here, but be careful not to add too much. Stretch keeping a square cross section. You will have to press and roll hundreds of times. Here I stretched out to 4 times the length. I'd really only recommend twice the length. Trim off the edges using a sharp knife. Cut evenly into pieces. Now stretch each of these and form into the next iteration. You'll have to use the eight pieces to surround another full sized alternate color piece. Stretch and cut. Stretch and cut again and again, until you have 8 evenly sized pieces. Use these to surround another full sized alternately colored piece. Press and stretch a little bit until you have a nicely formed fractal. Use a sharp knife to cut out the cookies. Bake and serve.

Show Off Your Work If you make these cookies or any of the other previous Math Craft projects, please share with us by posting to the corkboard. Maybe you just have something cool that you made or saw on the web—you can share that, too! If you like these types of projects, let me know in the comments. If you have any other ideas you would like to pursue, let me know in the forum. Next post, we're going to make some fractal cupcakes.