Preheat oven to 200 degree. Line a baking sheet with parchment paper or a silicone mat. Fill a medium sauce pan with about 2 inches of water and set over medium-low heat. Place heat-proof bowl over the top. Add sugar, egg whites, salt and cream of tartar. Mix together with a spatula. Continue to stir until sugar dissolves and mixture reaches between 150-160 degrees.
Remove mixture from heat and pour into bowl of a stand mixer. Add vanilla extract. Using the beater attachment, whisk egg whites over low speed for 1 minute. Increase speed to medium for 30 seconds and then keep increasing the speed slowly until medium-high. Whip until glossy, stiff peaks form. This should take no more than 8 minutes.
Spoon 12 even dollops over the baking sheet, leaving about 1 inch between each. Spoon about ½ teaspoon of caramel sauce in the center of the meringue and swirl in a circle.
Bake in preheat oven for about 1 hour 15 minutes. Turn off oven and let them cool in the oven for about 1 hour. They should be firm to the touch. If not, leave them in there for 30 more minutes. Remove from oven and let them cool completely before eating.