Heat oven to 250 degrees F. Line two large baking sheets with nonstick foil.

In a small bowl, whisk together the sugar, cocoa powder and ground cinnamon. Place egg whites into the bowl of a standing mixer, or a large bowl. Add the cream of tartar.

Begin beating egg whites on low speed, using the whip attachment, until foamy. Increase the speed to medium, and add sugar mixture, one tablespoon at a time, until medium-stiff peaks form.

Transfer mixture to a large pastry bag fitted with a large star tip (go to confectioneryhouse.com to purchase). Pipe onto prepared baking sheets. Bake at 250 degrees F for 1 hour, 15 minutes-do not open oven door or meringues may collapse. Turn off oven; let meringues sit in oven at least 1/2 hour, then remove baking sheets from oven. Carefully remove cookies directly to cooling racks. Cool completely.

Place semisweet chocolate in a small microwave-safe bowl. Microwave 1 minute, then stir until smooth. Transfer to a small plastic bag. Snip off a corner. Transfer meringues to a sheet of waxed paper. Drizzle with melted chocolate. Let dry completely. Store in airtight container at room temperature.