Place chocolate, butter, and corn syrup with 5 teaspoons of water in a small bowl. Melt gently in a barely simmering water bath over low heat, stirring frequently until almost completely melted. Do not overheat. Remove glaze from water bath and set aside to finish melting, stirring once or twice until glaze is perfectly smooth. Stir mixture gently with a spatula or a wooden spoon until completely smooth; do not whisk or beat. Use glaze at 88-90 degrees.
