In just about every area of the United States, except for New England, a milkshake is a heavenly mixture of milk, ice cream and flavoring. Sometimes this creamy drink includes malted milk powder -- making it into a "malt." A malt and a milkshake share a rich, thick consistency and come in similar flavors, such as vanilla and chocolate. The addition of malt powder though provides a distinct, sweet flavor that for many tastes gives an oomph to the shake.
Malt is essentially dehydrated milk with the addition of barley malt, wheat flour, salt and sugar. It makes a shake sweeter and alters the flavor. It's particularly popular in old-fashioned soda-shop style restaurants.
To create a malt -- or malted -- shake, blend one to three teaspoons with the ice cream, milk and any other flavorings, such as vanilla extract or chocolate syrup per serving. The more malt you add, the richer the shake will taste. You may add malt to any flavor of shake, but it's particularly popular with the classics of strawberry, chocolate and vanilla. In some cases, a malt may be a little thinner than a shake -- but this is a matter of the shake "chef."
A malt isn't necessarily superior to a shake, it's simply a different flavor. The candy, _Whoppers_, are chocolate-coated malted milk and give you an idea of the taste that results from adding malt to your shake. Some people have passionate opinions about adding malt to their shake: They love it or hate it. You have to decide on your own which is best.