Place egg whites in a mixing bowl of a stand mixer and beat with the whisk attachment
2 egg whites
When egg whites become foamy, add cream of tartar
¼ teaspoon cream of tartar
Whisk on high speed until soft peaks are formed and then slowly add sugar while whisking
½ cup sugar
Continue whipping until stiff peaks are formed
Sift cocoa powder into meringue and gently fold in until all cocoa powder is mixed
2 tablespoons unsweetened cocoa powder
Pipe 1 - 1 ½ inch stars onto a baking sheet lined with parchment paper
Bake in a preheated 300° oven for 45-60 minutes
Cookies are done when they pull off easily from the parchment paper and they are light and airy and dried all the way through
Notes
When separating eggs, make certain there isn't any yolk that accidentally gets in with the whites
Use a stand mixer with a whisk when possible. A hand mixer can also be used, but the mixing time will take longer. You could also use a hand whisk, but you might need muscles like Popeye!
Use a clean, dry mixing bowl
Be certain to pipe the cookies right away. Waiting may cause the meringues to deflate
Instead of piping you could also spoon a dollop of meringue onto the baking sheet
Use parchment paper or a silicone mat to bake meringues
The cooking time will vary depending on the size of your meringues and the humidity
Meringues are done when they easily lift off the parchment paper and are light. The cooking is actually drying out the meringues. They should be light and airy throughout.
Store cooled meringues in an airtight container for up to 2 weeks