There's never been a better time to eat — and cook with — American apple varieties.One day in 2004, Brooke Hazen noticed something unusual about one of his Golden Delicious apple trees. “Some people are lucky enough in their career to have their own bud mutation variety that they get to name,” says Hazen. “Out of the thousands of trees I have, one branch on one tree decided to do its own thing.” What it did was yield an apple with the typical green-yellow skin but an unusual pink patch where it faced the sun and a sweetness and fragrance...