In a large bowl, beat the egg whites and cream of tartar until soft peaks form. Gradually add the sugar and vanilla, beating until stiff peaks hold, sugar is dissolved and mixture is glossy. Sift in the cocoa, gently folding just to combine. Fold in the chocolate chunks. Drop by heaping Tbls onto parchment paper or foil lined baking sheets.
Bake at 300 for 35-45 minutes or just until dry. Carefully peel off of the paper and cool completely on a wire rack.
Store covered at room temp.
Not a NESTLÉ®-tested recipe.