Milkshakes are having a moment. That classic combination of milk, ice cream and fruit or syrup is an increasingly popular, utterly perfect match for steamy summer temperatures. And naturally, the most surefire way to turn something good into something great is by adding alcohol. (See also: coffee, watching baseball.) That’s what makes the latest crop of boozy milkshakes so winning. These adults’-only treats boldly go where no shakes had gone before.