Line a 13 x 9 inch pan with parchment and spray bottom and sides with cooking spray. Spray large bowl with cooking spray; place cereal in bowl, and set aside.
Spray medium microwavable bowl with cooking spray; add unwrapped caramels and water. Microwave uncovered on high for 2 1/2 minutes, stir after each minute until the mixture is smooth. Remove from microwave. Stir in marshmallows until melted and smooth.
Pour caramel mixture over cereal in bowl; stir until cereal is evenly coated. Pour cereal mixture into pan. with back of spatula sprayed with cooking spray, press mixture in pan until even.
In small microwavable bowl, microwave baking chips and oil uncovered for 1 1/2 minutes, stirring after 1 minute, until mixture is smooth. Drizzle melted mixture over top of cereal mixture.
Refrigerate until mixture is firm and glaze is set, about 30 minutes. Enjoy!