Start by preparing your baking pan. Line a 9x13-inch pan with parchment paper for easy removal of the bars later. This step is optional but highly recommended for keeping your bars intact.
In a medium saucepan over low heat, combine the 1/2 cup butter and the 10 oz package of butterscotch chips. Stir continuously until the mixture is completely melted and smooth. Be careful not to let it burn.
Remove the saucepan from the heat and add about 6 cups of the miniature marshmallows to the melted mixture. Stir until the marshmallows are fully coated and just beginning to soften. This should take about 1-2 minutes.
In a large mixing bowl, add the 8 cups of corn flakes and 1 cup of toasted coconut. Pour the melted butterscotch and marshmallow mixture over the corn flakes. Gently fold everything together until the corn flakes are evenly coated.
Fold in the remaining 2 cups of miniature marshmallows, creating a delightful mix of textures throughout the bars. The extra marshmallows give a nice chewy bite.
Transfer the mixture to the prepared baking pan. Using a spatula or your hands (lightly greased), press the mixture firmly into an even layer. This step is crucial to ensure the bars hold together once set.
Place the pan in the refrigerator for at least 1-2 hours, or until the bars are firm. This will help them set perfectly and make them easier to cut.
Once set, remove the bars from the pan using the parchment paper. Cut into squares or rectangles, and serve! These No Bake Butterscotch Cereal Bars are perfect for sharing or indulging all on your own.
