Hazelnut Brittle
["4 c. sugar", "1/4 tsp. apple cider vinegar", "5 1/2 c. hazelnuts"]
["Oil an 11 x 17 pan. Stir sugar, vinegar and 1 cup water in a medium sized, heavy bottomed saucepan over medium heat until sugar dissolves. Cook, without stirring, until dark amber, 18 to 25 minutes. Stir in nuts. Pour mixture into pan. Let set until firm but still soft enough to cut. Unmold onto a cutting board. Working fast, use an oiled knife to cut into 6 rectangles. Store in an airtight container up to 1 week."]
["sugar", "apple cider vinegar", "hazelnuts"]