Grease a 9x13-inch pan with butter. Set aside. (Note: This prevents the treats from sticking on the pan. You can also use cooking spray.)
Stovetop: In a large pot, melt the butter on medium-low heat.
Add Marshmallows: Once the butter melts completely, add 2/3s of the marshmallows into the pot (Note: Save ⅓ of the marshmallows for later!!!!). Stir continuously until the marshmallows are melted. The mixture should be smooth with no lumps.
Remove From Heat: Turn off the stove and remove the pot from the heat. Stir in the salt and vanilla extract.
Add Cereal: Add the Rice Crispy Cereal into the pot and fold.
Add Remaining Marshmallows: Once the cereal is coated in the melted mixture, add the remaining marshmallows. Continue to fold until the marshmallows are evenly distributed.
Pour the rice krispie mixture mixture into the prepared pan. Spread the mixture so that it is evenly distributed throughout the pan. Do NOT press down (see notes). It doesn't have to be perfect.
Let sit at room temperature for one hour. Then, enjoy!
No large pan? No Dutch oven? No problem! Melt the marshmallows on the stovetop. Then, transfer them into a large mixing bowl. Follow the rest of the recipe.
Do NOT press down on the mixture!!! This ruins the texture. The treats will be compact and difficult to eat.
Recipe Variations (Check Blog Post for more information):
Brown The Butter for a nutty flavor
Add chocolate chips at the end
Use different cereal! Fruity Pebbles would be a great substitution.
To Store: Store leftovers covered with plastic wrap at room temperature for 4-5 days. If you need to store them longer, you can freeze them in an airtight container for up to three months.