In a large saucepan, melt 1/4 cup butter and 4 cups marshmallows; stir until smooth. Stir in 4 cups cereal. Pat into a greased 13-in. x 9-in. pan; set aside.
For caramel filling, place the caramels and 10 tablespoons butter in another saucepan; cook and stir over low heat until melted. Stir in the milk until smooth. Cool for 10 minutes; pour over cereal layer. Refrigerate for about 30 minutes or until firm.
In a large saucepan, melt the remaining butter and marshmallows. Stir in remaining cereal. Spread over caramel layer. Cover and refrigerate for 30 minutes or until firm. Cut into bars. Store in the refrigerator.