Sprinkle gelatin over white milk in small bowl. Let stand 10 minutes. Meanwhile, heat 1 cup (250 mL) chocolate milk. Do not boil. Remove from heat. Add milk-gelatin mixture, whisking until dissolved, about 3 minutes. Whisk in remaining chocolate milk. Divide into 4 serving cups. Refrigerate until wobbly-set: 2-3 hours. Sprinkle with favourite cereal just before serving.