Melt the butter over medium heat in a large pot. Once melted, add the marshmallows.
Use a wooden spoon to constantly stir the marshmallows until they are mostly melted. Add the cacao powder, and stir until combined.
Remove the pot from the heat and add the rice cereal. Stir until mostly combined, then add in the almonds and chopped chocolate. Stir until everything is combined. This is going to take a couple of minutes.
Spray a 9x13 inch glass dish with coconut oil to prevent sticking. Pour the whole mixture into the dish and use your hands to flatten it out and make an even layer.
You can put them in the fridge if you like them cold, but they can also stay out at room temperature. Let them cool and firm up for about an hour before you cut into them.
Cut into 16 pieces and enjoy!