Preheat oven to 250°. Beat egg whites and cream of tartar in a deep bowl with a mixer, using whisk attachment if you have one, just until soft peaks form. Add vanilla and salt. With motor running and mixer on high speed, pour in 1 tbsp. sugar and beat 10 to 15 seconds, then repeat until all sugar has been added. Scrape inside of bowl and beat another 15 seconds. At this point, meringue should form straight peaks when beaters are lifted. Fold in chocolate chips and 1/3 cup candies with a flexible spatula.
Line 2 baking sheets with parchment paper, using a bit of meringue at corners as glue. Using a soup spoon, drop meringue in rounded 1-tbsp. portions slightly apart onto sheets, scraping off with another spoon. Sprinkle with remaining 1 1/2 tbsp. candies.
Bake until meringues feel dry and set when touched but are still pale, 30 to 35 minutes, switching pan positions halfway through. Turn off oven, open door, and let cookies stand about 10 minutes. Let cool on pans.
Make ahead: Up to 2 days, stored airtight.
Note: Nutritional analysis is per cookie.