Preheat the oven to 200 degrees Fahrenheit. Line two baking pans with parchment paper, and set them aside.
Separate the egg yolks from the egg whites and add the egg whites to a large mixing bowl. (Discard of the egg yolks, or add them to an omelet, or use them otherwise). 4 large egg whites
Add the cream of tartar and salt to the egg whites and mix them together on low speed until it becomes foamy. 1/4 tsp cream of tartar, 1 dash salt
Slowly increase the mixer speed to medium high, and add the sugar to the mixing bowl 1 Tablespoon at a time. Making sure the sugar is completely dissolved before adding the next tablespoon, this will take about 20-30 seconds between each addition. 1 cup granulated sugar
Continue to mix until the mixture is thick, shiny, and has stiff peaks. This will take several minutes.
Add in the vanilla extract, and green food coloring and mix until just combined. 1 tsp vanilla extract, green gel food coloring
Spoon the mixture into a large piping bag or ziplock bag with a large star tip.
Pipe the meringue about 2 inches across at the bottom, working up to make the shape of Christmas trees, each about 2 inches apart, until all the mixture is piped onto the cookie sheets.
Sprinkle non pareils on the bottoms of each meringue, and top each gently, and carefully with a candy star. 1 TBS non pareils, 1 TBS star sprinkles
Bake the pans in the oven for 2 hours.
Turn off the heat, and leave the pans in the oven for another 2 hours without opening the door, so they can completely dry out. They will be crisp on the outside and lift freely from the parchment paper.
Carefully remove from the parchment paper and enjoy, or store in an airtight container.