In a large pot, melt the butter over medium-low heat. Once the butter is almost completely melted, add the marshmallows.
Stir to coat the marshmallows fully in the butter. Cook for 5 to 8 minutes, stirring intermittently until the marshmallows melt completely. Don't overcook, as this will cause the mixture to burn and the marshmallows to harden.
Remove the pot from the heat. Stir in vanilla extract, peppermint extract, and salt.
Pour in the cereal. Stir to fully combine, making sure to scrape any additional marshmallows from the bottom of the pot.
Allow the mixture to cool for about 5 minutes before adding the white chocolate chips and crushed candy canes. Stir to combine.
Working with 1 at a time, scoop out ½ cup of the mixture and using your hands, shape it into a candy cane. You may need to spray your hands with nonstick spray to prevent sticking. Continue to form the rest until you have 16 equal sized treats.
Peel the candy ropes so they're 2 strings thick. Twist the strings tightly around the shaped candy cane rice krispie treats to resemble the red stripes on a candy cane.
Use your fingers to press the candy strings into the rice krispie treats so they don't unravel.