In a stovetop pot over medium-low heat, add in the butter, salt, marshmallows and cacao powder.
Keep stirring until the butter and marshmallows are melted and it becomes one mixture.
Stir in the chocolate chips until they are melted and incorporated into the mixture.
Add in the rice krispies to the mixture, one cup at a time, stirring in between until mixed.
Once it all becomes one big mixture, remove from heat and pat down into a baking tray lined with wax paper or greased.
If your baking tray is not the right size, it will still fit - which is the beauty of Rice Krispies! They don't expand, so you can shape it into your tray (even if only half the tray is needed). Make sure your hands are greased with butter to be able to pat down the mixture (otherwise the marshmallows will stick to your hands and it'll be impossible to pat down).
Let them set for 2 hours at room temperature. Once they have cooled down, cut into 16 squares and enjoy!
Store in an airtight container at room temperature.