Traditional Rice Krispies Treats are taken to a whole new level thanks to a few clever tricks. You’ll begin by browning two sticks of salted butter until nutty and dark. Then you’ll add two bags of mini marshmallows, vanilla extract, and a splash of bourbon for good measure. While most Rice Krispies Treats recipes simply melt the marshmallows and butter together and call it a day, this recipe cooks them over medium-high heat for several minutes until they transform into a thick marshmallowy caramel. (A trick we learned from The New York Times.) This step does two things: It adds a deep, toffee-like flavor and gives them a beautiful golden color—but it also causes the marshmallows to harden—so to compensate, one more bag of marshmallows is added right at the end so you get the best of both worlds. Sure, it’s a bit more work compared to your classic Rice Krispies Treats recipe, but it’s totally worth the effort.
Grease a 9x13-inch baking pan with butter. Set aside.
In a very large pot set over medium-high heat, melt butter, stirring constantly, until the milk solids at the bottom of the pan start to brown and the butter smells nutty and darkens in color. This will take about 5 minutes. Do not walk away or leave unattended.
As soon as the butter has browned, add two bags of marshmallows, the bourbon, vanilla, and salt. Cook for 5 to 6 minutes, stirring constantly, until the mixture is golden, smells like caramel, and is smooth and glossy.
Turn off the heat, add the remaining bag of marshmallows, and stir just until melted. Add the rice cereal and quickly stir to coat them with the marshmallow mixture. (If your pot is not big enough, quickly transfer the mixture into the largest mixing bowl you have.)
Transfer into the prepared baking pan and gently press into an even layer. If the mixture is too sticky, coat your hands in butter or oil to make it easier to work with. Garnish with flaky salt. Let cool completely and cut into squares.