Add the shredded coconut to a dry pan over medium-low heat. Toast, stirring frequently, until golden brown and fragrant. Keep a close eye on it because coconut can burn quickly.
Add the toasted coconut and Rice Krispies cereal to a large bowl. Gently mix until evenly combined.
Melt the butter in a large pot over low to medium-low heat. Add the marshmallows and stir continuously until completely melted and smooth.
Once the marshmallows are smooth, remove the pot from the heat. Quickly stir in the pandan extract until evenly incorporated.
Immediately add the Rice Krispies and toasted coconut mixture to the pot. Gently fold everything together until the cereal is evenly coated with the marshmallow mixture.
Quickly transfer the mixture to a parchment-lined baking pan. Gently press it into an even layer. Don't press too firmly, or the treats can become dense and hard.
Allow the Rice Krispie treats to cool and set completely before cutting.
Melt the white chocolate until smooth. Transfer it to a zip-top bag, snip off a small corner, and drizzle the chocolate over the Rice Krispie treats.
While the chocolate is still melted, sprinkle the top with additional toasted coconut.
Enjoy.