Lightly grease the bottom of a 9x13 baking pan with cooking spray and line with parchment paper.
In a large pot over low heat, melt the butter and stir in the salt.
Set aside 1 ½ cups of mini marshmallows to mix in later. Then pour the remaining marshmallows into the pot with the butter and melt over low heat. Make sure to stir constantly so it does not burn and remove the pot from the heat as soon as it is melted.
Once the marshmallows have melted, remove the pot from the heat and add the rice krispies cereal, the 1 ½ cups of mini marshmallows set aside earlier, 1 cup of Reese’s peanut butter cup minis cut in half, ½ cup peanut butter chips, and ½ cup semisweet chocolate chips. Gently fold together until evenly combined.
Pour the mixture into the baking pan and spread it out evenly. Do not pack it in too tight otherwise it will become hard to eat.
Top with the remaining Reese’s peanut butter cups, peanut butter chips, and semisweet chocolate chips and gently press it into the bars to help them stick.
Allow to cool in the pan on the counter for 30-45 minutes before cutting into bars. Enjoy!
Notes
For slightly thinner bars, use an 11x14 inch pan instead. Swap the peanut butter chips with Reese’s pieces, M&M’s, or chopped nuts. This recipe will work with Cocoa Krispies or even Cocoa Pebbles.Avoid pressing the mixture too tightly or it may result in hard treats. Gently pack them in instead.Store leftovers in an airtight container on the counter for up to 2 days. To soften treats, heat in the microwave for 5-10 seconds.