01 -
Lightly grease a 9×13-inch pan with butter or cooking spray and set aside
02 -
In a large pot, melt butter and peanut butter over medium heat, stirring until smooth. Add marshmallows and stir constantly until melted and combined
03 -
Remove from heat and stir in vanilla extract and fine sea salt
04 -
Add Rice Krispies cereal to the pot, gently folding until fully coated
05 -
Transfer mixture to the prepared pan, pressing down gently with a greased spatula or oiled hands
06 -
Sprinkle flaky sea salt over the warm mixture, if desired
07 -
Let the treats cool at room temperature for 30 minutes. Slice into squares and enjoy!