1Preheat oven to 300 degrees F (150 degrees C). Grease baking sheets or line them with parchment paper.
2In a medium bowl, whip egg whites to soft peaks. Gradually add the sugar, vinegar and vanilla while whipping to stiff peaks. Fold in chocolate chips. Drop by spoonfuls onto the prepared cookie sheets.
3Bake for 20 to 25 minutes in the preheated oven, until cookies are dry.
Footnotes
Tip
Parchment can be used for easier cleanup/removal from the pan.