Melt 4 tablespoons (half a stick) of unsalted butter in a large pan over medium heat, add in 1/8 tsp of salt.
Once the butter is fully melted, add in all the marshmallows. Continuously stir with a rubber spatula to prevent burning.
When most of the marshmallows are melted, add in ½ tsp of pandan extract or vanilla extract. Mix until well incorporated.
Leaving the pot on the stove, turn off the heat and add in all of the crispy rice cereal into the pot and gently fold the marshmallows into the cereal. Work relatively quickly to prevent the marshmallows from hardening.
Line a 8 x 8 inch square baking pan with either wax or parchment paper. If you don’t have either of those, spray or butter a thin layer of oil to all sides of the pan and transfer the mixture in the pot to the pan.
Spray your fingertips with some oil, and gently press down on the rice krispy mixture. Don’t pack them in too tightly or they’ll lose the fluffy buttery texture.
Cover and let rest at room temperature for 45 minutes. Cut, serve, and enjoy!