01 -
Melt unsalted butter in a large sauce pan or pot over low heat, ensuring the butter is completely liquefied and not browned.
02 -
Add mini marshmallows and cocoa powder to the melted butter. Stir continuously over low heat until the marshmallows are almost fully melted and the cocoa powder is well blended.
03 -
Remove the pan from heat. Gently fold in Rice Krispies cereal in two additions, mixing until cereal is mostly coated in the chocolate marshmallow mixture.
04 -
Fold in semi-sweet chocolate chips until evenly distributed throughout the mixture.
05 -
Scoop the mixture into a prepared 8x8-inch or 9x9-inch pan lined with parchment. Gently press the mixture into an even layer without compacting too firmly.
06 -
Sprinkle additional chocolate chips and flaky salt on top, if desired. Let the bars set at room temperature for at least 30 minutes before slicing.