Gooey Caramel Popcorn

We have this every 4th of July while we watch fireworks
Recipe from Cindy Gillette

1 can sweetened condensed milk
1 cube butter
2 cups brown sugar
1 cup light corn syrup
3 gallons popped popcorn

Mix butter, sugar and corn syrup. Bring to a boil. Add milk. Cook to soft ball stage (228 degrees). Pour over popcorn and stir.