Start by chilling a martini glass by adding a little water along with some ice cubes. Gently swirl and when the glass becomes frosted, drain and set aside.
In a cocktail shaker, add a few ice cubes, vodka, sour apple schnapps and sweet and sour mix. Close tightly and shake vigorously for 8-10 seconds.
Take the cap off and pour into martini glass (without the ice cubes).