Fill your cocktail shaker halfway with ice cubes, allowing it to cool thoroughly.
Add the vodka, green apple schnapps, lime juice, and sour apple syrup directly into the shaker over the ice.
Secure the lid tightly and shake vigorously for about 15 seconds, until the mixture is well chilled and slightly frothy.
Remove the shaker lid and place a strainer over the opening to catch any ice shards or pulp.
Strain the cocktail into a chilled martini glass, allowing it to flow smoothly for a glossy, vibrant green appearance.
Garnish with a thin apple slice or a spooky edible decoration for an extra eerie touch.