When British pharmacist James Horlicks and his brother William developed malted milk in the late 19th century, they didn't intend for it to become a dessert. Made from malted barley, flour and powdered milk, malted milk was originally intended as food for infants. However, malted milk soon caught on among other markets, including explorers, who liked it for its easy portability. It appears to have been in the early 20th century that people began incorporating malted milk's rich, sweet flavor into desserts. Horlicks' original product remains popular as a nutrition drink for children in India.

As milkshakes and similar desserts gained in popularity following the introduction of the electric blender and freezer, malted milk became a common ingredient. A "frosted malted milk" was made with ice cream and malted milk powder, to create a frozen dessert with a rich, roasted taste. A malt was typically thicker than the more liquid milkshake; a 1939 ad for frosted malteds describes them as "the drink you eat with a spoon."

The key ingredient in a frosted malted is malted milk powder; this can be found near powdered milk in most supermarkets. As with milkshakes, the exact recipe for a malt can vary, but the basics are the same. A 3-to-1 mixture of chilled milk and ice cream are blended together with a small amount of malted milk powder until they reach a smooth, creamy consistency. For a single serving, a tablespoon of malted milk powder should do it. A malt should be served in a tall chilled glass.

By the 1930s, frosted malteds were a popular sweet treat. By 1940, the US Department of Agriculture was tracking consumption of frosted malteds as part of its overall survey of consumption of milk products. Frosted malteds were served in restaurants and drugstores, as well as small stands. No longer a standard, frosted malts can still be found in some ice cream parlors and restaurants whose menus preserve these traditional desserts. Because of this association, malts make a great treat for 50s-themed parties.