Preparation

To prepare the hazelnuts:

• Heat the oven to 350°F. Spread the hazelnuts in a single layer on a baking sheet and toast in the heated oven until the skins are mostly split and the nuts are light golden brown and quite fragrant, 15 to 18 min. Don’t overcook the nuts or they’ll become bitter.
• Put the warm hazelnuts in a clean dishtowel. Fold the towel around the hazelnuts and let them steam for at least 5 min. Then rub the nuts in the towel to remove most of the skins (try to get at least 50% of the skins off). Let the hazelnuts sit for another 10 to 15 min. to cool completely. Toasted, peeled hazelnuts can be cooled and frozen in a sealed plastic container for up to three months.

To make the hazelnut butter:

• Put the nuts in a food processor; add the oil and pulse a few times. Then process, checking the consistency every few seconds, until the texture resembles that of natural, unhomogenized peanut butter or wet sand, 1 to 2 min.