Fill a glass with ice.
Pour 3 tablespoons of homemade apple syrup over the ice.
Add 2 ounces of freshly brewed espresso (cooled) or prepared instant espresso. Stir the espresso and apple syrup together.
Pour in ¾ cup oat milk and gently stir.
Make the cold foam by adding the dairy-free heavy cream, 2 tablespoons oat milk, vanilla extract, maple syrup, and salt to a small glass or frothing container.
Froth the mixture with a handheld milk frother until it becomes thick and creamy.
Pour or spoon the dairy-free cold foam over the iced apple cinnamon latte.
Drizzle additional homemade apple syrup over the cold foam, if desired. Serve immediately.