Gluten Free Rice Krispie Treats

0 Melt the butter & marshmallows. Add butter to a medium pot over medium-low heat, stirring it gently until the butter melts. Once butter is melted, add marshmallows to the pot, stirring often until melted. The marshmallows will form a bit of a paste, like that of marshmallow fluff.
1 Add remaining ingredients. As soon as the marshmallow has melted, immediately remove the pot from the heat. Working quickly, add vanilla extract, gluten free rice cereal & protein powder, if using, to the marshmallow and fold it in using a wooden spoon or spatula. Continue folding until all ingredients are well mixed & rice cereal is coated with gooey marshmallows.
2 Press into baking dish. Using your spatula or wooden spoon, guide the mixture into an 8x8 prepared pan lined with parchment paper or greased with cooking spray, pressing down gently until the rice krispies treats are in an even layer in the pan. Allow the rice krispies treats to cool at room temperature for about 10 minutes before slicing into 9 individual treats. For best results, use a serrated knife when cutting.