Wash and thoroughly dry the apples. Slice them into thin-ish (ΒΌ") slices and remove any seeds or stems. Insert popsicle sticks through the bottom. If the slices are too thin, do a test trial before slicing all your apples to avoid breakage.
Put chopped chocolate (or chocolate chips) in a heat-safe bowl. Microwave in 30-second intervals, stirring well between each, until completely melted. Optionally, add 1 tablespoon of coconut oil to thin it out for easier dipping.
Dip each apple slice in chocolate, using a spoon to coat the entire slice. Allow excess chocolate to drip off, then transfer to a parchment paper-lined tray.
Add dry toppings like nuts, cookies, sprinkles, chocolate chips, or coconut right away. Refrigerate or freeze until solid. For toppings like caramel or peanut butter, let the chocolate harden first before adding. Store in the refrigerator for 3-4 days.