Preheat oven to 275° F. Prepare 2 cookie sheets with aluminum foil, shiny side down or parchment paper.
In the bowl of your mixer, using the whisk attachment on a medium speed, beat egg whites and salt until frothy, about 1-2 minutes.
Add vinegar and beat until soft peaks form, about 2 minutes. Slowly beat in sugar and cream of tartar until stiff peaks form, about 2-3 minutes.
Beat in vanilla flavoring until incorporated, about 1 minute. Then fold in chocolate chips.
Spoon mixture into piping bags and pipe into desired shape onto the cookie sheets. Leave about 1-2 inches apart, they don't spread. Or if dolloping just use a spoon to make cookies.
Bake 40 minutes, turning cookie sheets after first 20 minutes.
Cool and serve. Store airtight for a few days if needed.
Notes
*For baker's sugar I take granulated sugar and pulse it in the processor for about 30 secs to a minute.**In order to get my chocolate small enough to go through the piping bag I also put it in the processor and pulse for a bit. You can use normal chips however or bigger chunks if you plan on dolloping.