Mix with cream of tartar and salt until frothy
Slowly add granulated sugar, a spoonful at a time, until whites are stiff and glossy.
Whisk together cocoa and powdered sugar, then gently fold into meringue.
Gently fold in finely chopped chocolate
Pipe or dollop onto sheet pans and bake until firm and no longer sticky, 1 hour.. Turn off the oven and let meringue cookies dry out for at least another 1 1/2 hours.
SERVE WITH COLD MILK!