Peel the bananas and slice them into rounds, about 1 inch thick. You should get about 24 to 30 slices.
Place the banana slices on a baking sheet lined with parchment paper.
Freeze the banana slices for at least 2 hours, or until completely solid.
In a microwave-safe bowl, combine the chocolate chips, coconut oil, and vanilla extract.
Microwave in 30-second intervals, stirring well after each interval, until the chocolate is smooth and fully melted.
Remove the frozen banana slices from the freezer. Working quickly, dip each frozen slice into the melted chocolate, turning to coat one side or both sides.
Place the dipped slices back onto the parchment-lined baking sheet.
If using toppings, immediately sprinkle them over the wet chocolate.
Return the coated banana bites to the freezer for at least 30 minutes to allow the chocolate shell to harden completely.
Serve directly from the freezer.
Notes
For a dairy-free or vegan option, use dairy-free chocolate chips.
If you do not have coconut oil, vegetable shortening works well to keep the chocolate smooth for dipping.
Store leftovers in an airtight container in the freezer for up to one month.