Preheat the oven to 350° Fahrenheit.
In a medium-size bowl, mix flour, baking soda, and salt together. Set aside.
Mix one or two small drops of RSO into melted butter until completely combined.
In a large mixing bowl, combine melted butter, brown sugar, white sugar, peanut butter, vanilla, and egg. Mix until smooth.
Add dry ingredients slowly and mix until combined.
Scoop a tablespoon of dough, roll into a ball, and then roll into sugar.
Transfer dough balls to a baking sheet.
Using your fork, press down on the balls to flatten slightly.
Bake for 10-13 minutes, just until the edges are slightly brown.