1. In a heavy-bottomed medium saucepan (no larger than 2 quarts, or the mixture will reduce too rapidly and burn before it reaches the correct temperature) over high heat, bring the sugar, water, and chocolate to a boil over medium-high heat, stirring occasionally. Attach a candy thermometer to the pan. Reduce the heat to medium and cook, uncovered, stirring, until the mixture reaches 234°F., about 5 minutes. 2. Remove from the heat and stir to cool and thicken slightly, about 1 minute. Use immediately. When pouring, do not scrape the pan. Use 1 cup sugar, 1/2 cup water, and 4 ounces bittersweet chocolate. Make the glaze in a small saucepan.