Preheat the oven to 300°F and line a baking sheet with parchment paper.
Separate 3 egg whites into a bowl and set them aside.
3 large egg whites
Into a medium bowl, sift the cocoa powder, sweetener, and salt and set aside.
½ cup unsweetened cocoa powder, Pinch of salt
Beat the eggs on low to medium speed until frothy.
Add the cream of tartar and turn the speed to high and continue beating until soft peaks just form.
⅛ teaspoon cream of tartar
Continue beating the eggs while adding the sugar gradually.
¼ cup granulated sugar
Once the sugar has been added, continue beating until the stiff peaks form then stop beating.
⅓ cup Splenda
Fold in the sifted cocoa mixture along with the vanilla extract a little at a time until just incorporated.
1 teaspoon vanilla extract
The mixture will change texture and while you don't want to over mix this, you will begin to see a thicker frosting consistency.
Drop small spoons of the mixture onto the baking sheet.
For chewy cookies, bake for 20 minutes. If you prefer the crunchy texture, continue baking for 40 minutes.