Barely adapted from Ellen Jackson. Unlike almost any other drop cookie I make, DO NOT rest this dough. The vinegar will activate the baking soda instantaneously, so you want to get them in the oven quickly. Do your best to split all of the dough between 2 cookie sheets, 20 cookies to a sheet. I had a little leftover, and wished I had just made the cookies a tad bigger because the later batch of about 7 cookies was noticeably flatter.