2 cups hazelnuts, mostly skinned
1/4 cup sugar
1 pound semisweet or bittersweet chocolate, coarsely chopped
1 stick unsalted butter, cut into pieces, at room temperature
1 tablespoon of pure Vanilla Extract
1 cup heavy cream
1 /4 teaspoon salt
Preheat the oven to 350 degrees F. Spread the nuts on a baking sheet and roast until deep brown, about 15 minutes. Let cool completely. Rub the nuts in a kitchen towel to remove the skins.
Grind the hazelnuts and sugar in a food processor until a paste forms, about 1 minute.
Place the chocolate in a medium metal bowl. Set the bowl over a large saucepan of simmering water until the chocolate is melted. Remove the bowl from the heat; then add the butter and vanilla and whisk until completely incorporated. Whisk in the cream and salt, then the hazelnut paste.Pour gianduja into jars, dividing equally. Let cool.