Butter a 9×13 pan (or use non-stick cooking spray). Set aside.
In large pot, melt butter and marshmallows over medium heat.
Remove pot from heat and add coconut oil, peanut butter, honey, oats, and Rice Krispie cereal. Stir until evenly coated. Sprinkle in chocolate chips and mix until incorporated.
Press evenly into the buttered 9×13 pan with a cup that’s also been buttered, so the mixture doesn’t stick to the cup. When slightly cooled, sprinkle additional chocolate chips on top and press them lightly into the bars. Cut into squares when cool.