These rice krispy bars are chewy, gooey, and absolutely delightful! My homemade marshmallow is what puts them over the top!
Boil until it reaches 240°F and then remove the pan from heat. (this usually takes about 6 minutes)
Turn the mixer to low and add in melted butter, vanilla, and salt. Allow to mix on high for another minute or so and then remove the bowl from the stand mixer.
There is a video showing how I made homemade marshmallow for rice krispy bars here. (clickable link)