4 ounces (¼ pound or 1 stick) unsalted butter, plus extra for the pan
1 10-ounce bag marshmallows
½ teaspoon coarse sea salt
6 cups Rice Krispies cereal
Butter (or coat with non-stick spray) an 8-inch square cake pan with 2-inch sides.
In a large pot, melt butter over medium-low heat. It will melt, then foam, then turn clear golden and finally start to turn brown and smell nutty. (For me, this always takes just a bit longer than I think it should. Be patient.) Stir frequently, scraping up any bits from the bottom as you do. (Deb says: “Don’t take your eyes off the pot as while you may be impatient for it to start browning, the period between 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 turns the right color, take the pot off the heat and stir in the marshmallows. The butter should still be hot enough to melt the marshmallows, but when I made this, I had to turn the burner back on low heat for a minute to get the job done. You want the marshmallows to be melted until they’re smooth.
Remove the pot from the stove and stir in the salt and cereal together. Quickly spread into prepared pan. Use a silicon spatula or a piece of parchment paper sprayed with oil to press the treats down into the pan’s corners.
Let cool and cut into squares. Now, exercise self-restraint.