Pour the rice krispies and mix-ins (that last ingredient is your choice) in a large mixing bowl. Set aside. Melt the coconut oil and peanut butter in a saucepan over medium heat. Turn the heat down to low and add the marshmallows and stir until the marshmallows are mostly all melted. Add in the vanilla and protein powder.
Once fully melted, take them off heat and pour over the rice krispies. Stir lightly to combine. Dump into a lightly greased 9x9 pan and let sit 5 minutes. Then go and lightly press into the pan with greased hands. Allow them to cool about 20 minutes, then enjoy!
Depending on your protein powder and type of mix-ins used, the protein count per serving for these can range from about 6.5 - 7.5 g. (for 12 servings).