Pop 1-1/2 cups of popcorn (I used 4-6 bags of microwave popcorn sometimes) and spread out on 2 cookie sheets about 2 inches high. Sprinkle popcorn with nuts, if desired. Then cook the following:
1 can sweetened condensed milk
2 cups brown sugar
1 C. light corn syrup
1 cube (1/2 c.) butter
Cook the above ingredients to soft ball stage. 240 degrees on candy thermometer. Pour over popcorn and mix in or form into balls.