Preheat the oven to 250 degrees F. Line one or two baking sheets with parchment paper, depending on the size.
Using an electric mixer with the whisk attachment, beat the egg whites on medium speed until frothy, then add the salt, cream of tartar, and vanilla extract. Increase the mixer speed to medium-high and beat to soft peaks. While continuing to beat the egg whites, gradually add the granulated sugar (I estimate that I added about 3 tablespoons at a time) and beat until glossy and stiff peaks form. Using a rubber spatula, gently fold the chocolate chips into the meringue.
Drop by heaping tablespoonfuls (or use a medium cookie scoop), onto the prepared cookie sheets. If you could fit all of the cookies on one sheet, bake it on the center rack. If you have to divide the cookies between two sheets, then adjust your racks to the upper middle and lower middle positions. Bake for 25 to 30 minutes, or until firm to the touch (if using two oven racks, then rotate the sheets halfway through baking).Turn off the oven and prop the oven door open with a wooden spoon. Allow the pavlova to cool completely in the oven (will likely take 2 to 3 hours). As soon as the cookies have cooled, store them in an airtight container in the refrigerator or at room temperature. They will keep for up to 2 weeks.
Adding the sugar gradually during beating the egg whites keeps the meringue from collapsing, so don't be tempted to add it all at once or in large amounts.
Allowing the cookies to cool completely in the oven keeps them super crisp, and avoids that too-chewy texture. Store them as soon as they've cooled.