Mint Chocolate Pinwheel Cookies

My mom used to make a red and white mint version of these at Christmas, and I always liked both their straightforward flavor and their general cuteness.  This recipe is a veganized, chocolatized homage to those Christmas cookies of yore.  Makes about 2 dozen small cookies.

The Ingredients:
1/2 c sugar
6 T margarine, at room temperature
3 T almond milk
1 1/2 c flour
2 T arrowroot
1/4 t salt
1/4 t baking soda
2 T cocoa powder
1 oz. dark chocolate, melted
3/4 t mint extract

The Process:

1. Cream together margarine and sugar with an electric mixer.
2. Beat in almond milk.
3. Beat in flour, arrowroot, salt, and baking soda.
4. Divide dough in half.  Mix one half with the cocoa and melted chocolate, and the other half with the mint extract.  Form each flavor dough into a disc, cover in plastic wrap, and refrigerate about 30-45 minutes.
5. Preheat oven to 350 degrees.
6. Roll out both pieces of dough into 8"x7" rectangles. (This is easier if you sandwich the dough between 2 sheets of waxed paper, to prevent sticking.)
7. Stack the chocolate dough rectangle on top of the mint dough rectangle.
8. Starting with a long side, roll the dough up tightly, pressing down a bit as you roll so you end up with a cylinder about 9" long.
9. Cut the cylinder into rounds about 1/4-1/3 inch thick.  Place rounds on a parchment-lined baking sheet, and bake for about 12-14 minutes.