Add the gluten free flour blend and salt and mix until combined. If the dough seems too wet, add a bit more gluten free flour. (I find that with gf flour blends, some of them soak up the wet ingredients more than others. If your dough seems too wet for sugar cookies, add some more flour. The dough should be pretty stiff).

Place the dough on plastic wrap and shape into a log, about two inches square. Wrap and put in the refrigerator for at least two hours.

Add the gluten free flour blend, cocoa, and salt and mix until combined. Same as above, if the dough seems too wet, add a bit more gluten free flour.

Place the dough on plastic wrap and shape into a log, about two inches square. Wrap and put in the refrigerator for at least two hours.

Unwrap and with a very sharp knife, cut each log into three even slices. Then cut each slice into three pieces. Try to get the pieces pretty even, so that you can have a nice neat checkerboard. I was not as careful as I should have been, so my checkerboard was not perfect.

Take the dough pieces and arrange them into the checkerboard pattern. Your cookie will be three rows tall and three rows across. So bottom row, choc/van/choc, middle row, van/choc/van, top row, choc/van/choc. You will be making two logs, so the other log will have the opposite pattern.

Use your hands to kind of press the log, making sure the pieces stay together, then wrap each log in wax paper and twist the ends closed. You want to make sure the log is square, so press each side against the table to make a nice sharp edge.

Refrigerate for at least two hours, or overnight.

Preheat oven to 350 degrees. Line a cookie sheet with parchment paper.

Remove dough from refrigerator, and unwrap. With a very sharp knife, slice the cookies, about ¼ inch thick. In between each slice, wipe off the knife, and turn the dough over, so a different side is against the cutting board for each slice. This will keep the log nice and square.

Bake at 350 degrees for about 10 minutes. Cool on wire rack. (Keep the remainder of the dough refrigerated in between batches. Keeping the dough very cold makes it easier to slice and keeps it from spreading).