For easy drizzling, spoon the melted chocolate into a small food-storage plastic bag. Snip off one tiny bottom corner and squeeze the chocolate over the cereal mixture.
In large microwavable bowl, mix cereals.
In medium microwavable bowl, microwave caramels, butter and milk uncovered on High 2 to 3 minutes, stirring after each minute, until caramels are melted and mixture is smooth. Pour over cereals; gently stir until evenly coated.
Microwave on High 3 to 4 minutes, stirring after each minute, until just beginning to brown. Spread on waxed paper to cool.