Line a baking sheet or cooling rack with parchment paper and prepare two forks to handle the walnuts.It's essential to prep the equipment in advance as the caramel cools down quickly, and you won't have time to do so later.
Next, toast the walnuts. You can do so in a non-stick skillet on the stove on medium heat for a couple of minutes.Or you can toast them in an air-fryer for about 3 minutes or in the oven for about 6 minutes, in both cases at 350°F or 180°C.
Add the sugar to a small saucepan with a heavy bottom.
Melt the sugar on medium-low heat until it turns into syrup. It should take 1 to 2 minutes.Stir occasionally with a silicon spatula or with a spoon to prevent the sugar from burning, especially around the edges of the pot. Don't stir too much; it'll mostly melt on its own.
When the sugar has completely melted and reached arich orange-brown caramelcolor, turn off the heat. Add a pinch of salt and the toasted walnuts.
Carefully move the walnuts in the caramelized sugar, and try to coat each piece with the help of a fork. This should take you about 1 minute.
Transfer the nuts-sugar mixture to the parchment-lined baking sheet and separate the nuts from one another with a fork.Try to arrange them on a single layer. You need to work quickly as the sugar cools down fast.
Let cool down completelyin a dry corner of your kitchen and away from the sun until the sugar has hardened (about 30 minutes).