Step 1 Melt the chocolate and cocoa butter in a double boiler, or heatproof bowl placed over a small saucepan filled with 1 cup of water, over medium heat.
Step 2 Let the melted chocolate cool to room temperature. In the meantime, separate the egg whites from the egg yolks. Using an electric mixer, beat the egg whites and cream of tartar. As the egg whites thicken, slowly add the powdered Erythritol. Beat until they create stiff peaks.