8 tablespoons (1 stick) unsalted butter
One bag (250 gram) marshmallows
Heaping 1/4 teaspoon coarse sea salt
6 cups Rice Krispies cereal
Butter an 8-inch square cake pan with 2-inch sides.
In a large pot, melt butter over medium-low heat. The butter will melt, then foam, then turn clear golden and finally start to turn brown and smell nutty. Stir frequently, scraping up any bits from the bottom as you do. Don’t take your eyes off the pot -- the time the butter begins to take on color and the point where it burns is often less than a minute.
As soon as the butter takes on a nutty color, turn the heat off and stir in the marshmallows. Remove the pot from the stove and stir in the salt and cereal together.
Quickly spread into prepared pan. Use a piece of parchment paper to press it firmly and evenly into the edges and corners.
Let cool, cut into squares and enjoy!