Laura's Caramels

2 cups sugar
3/4 cup light corn syrup
1/2 cup butter (do not substitute margarine)
1 13 oz can evaporated milk
1 tsp vanilla
nuts (optional)

Mix sugar, corn syrup, butter and half of the milk in a large saucepan. Bring to boil over Med/High heat stirring constantly. Add the rest of the milk and reduce heat to Medium. Stir constantly until mixture reaches 232F on a candy thermometer (about 25 minutes). Remove from heat and add the vanilla and nuts. Pour into a buttered 9-inch square pan. Cool. Cut into squares and wrap in waxed paper. Store airtight.