Source: Oregon Hazelnut Industry and The Hazelnut Marketing Institute

1 pound roasted Oregon hazelnuts (3 1/2 cups)
6 tablespoons egg whites (about 3 large)
2 cups confectioners' sugar
2 teaspoons hazelnut liqueur

Yield: 2 to 3 cups.

Coarsely chop the hazelnuts. In a food processor or blender, finely grind about 1/3 of the nuts at a time, until mealy. Add egg whites, confectioners' sugar and liqueur. Blend until paste forms. Wrap and store in a covered container, up to 2 weeks.