To make a Soviet milkshake, like in childhood, you need to beat milk, creamy ice cream and your favorite fruit syrup in a blender. The cocktail should be cold when serving, so the products should be frozen. A milkshake like in the USSR according to GOST will turn out more airy and tender if you use high-fat milk. In Soviet times, by the way, a blender or mixer was rare, so a milkshake could only be bought in cafeterias.