Step 1.  Preheat the oven to 225 degrees F and cover a cookie sheet with parchment paper.

Step 2.  Place egg whites in a clean dry bowl and beat with an electric mixer on medium-high speed until foamy. Add cream of tartar, increase speed to high and whip until mixture forms soft peaks. Gradually add granulated sweetener and continue beating until whites are stiff and glossy.

Step 3.  In a separate bowl, sift powdered sweetener with the cocoa to blend. Working in thirds, sprinkle cocoa mixture over egg whites and gently fold in until thoroughly incorporated. There should be no dry cocoa powder in the final mixture.

Step 4.  Drop 12 cookie-sized dollops onto the cookie sheet with a spoon or ladle.

Step 5.  Bake for 1 hour, until meringues are firm and dry. Turn oven off and let meringues sit in oven for 15 more minutes.

Step 6.  Let meringues cool on sheets on wire racks, then gently peel the cookies off the parchment paper.