MISE EN PLACE
6 ounces bittersweet chocolate, chopped finely
2 large egg whites
1/8 teaspoon cream of tartar
1/4 cup sugar
1/2 teaspoon vanilla extract
Melt the chocolate in a double boiler. You can make your own double boiler by fitting a bowl over a pot of about the same width. Fill the pot with about 2" of water. Place the bowl of chocolate over the pot. The bowl should sit inside the pot, with plenty of room between the bottom of the bowl and the water. DO NOT GET ANY WATER IN THE CHOCOLATE. It will make the chocolate seize up and harden, rather than melt smoothly.
Once the water in your double boiler comes to a boil, turn down the heat to a simmer. There will be enough heat from the steam under the bowl to melt the chocolate. Once the chocolate is melted, turn off the heat, and stir the chocolate to melt any lumps.
TIPS FOR "PEAK" EGG WHITE SUCCESS
- Keep your eggs at room temperature (at least 1 hour before baking).
- Be careful when separating the yolks from the whites. Don't break the yolks!
- Add a pinch of Cream of Tartar to help stabilize whites.
- Use a medium-high setting on your mixer, and be patient. Before you know it, you'll have stiff peaks!
If all goes well, your cookies should have a light, cakey texture inside. Store cooled cookies in an airtight container for up to one week. They are delicate, so transport them in a structured container rather than a bag.
For a variation, replace the vanilla extract with peppermint, orange, or almond extract. These tend to have a much stronger flavor, so use 1/4 teaspoon or less.
You can double the recipe, but may loose some volume in the process. I get better results by making the recipe twice. One recipe makes about 24 cookies.