Ingredients
Vegetable oil, for pan and knife
4 cups sugar
1/4 teaspoon apple-cider vinegar
5 1/2 cups hazelnuts
Preparation
Combine sugar, vinegar, and 1 cup water in a medium saucepan set over medium heat until sugar dissolves. Cook until dark amber in color, 20 to 22 minutes. Stir in nuts.
Oil an 11-by-17-inch baking pan. Pour hot mixture onto pan. Let set until firm but still soft enough to cut. Invert onto a cutting board, and unmold. Working quickly, use an oiled chef’s knife to cut the sheet into six rectangles. Store brittle in an airtight container up to 1 week.
