How to Make It
Combine bittersweet chocolate (or white chocolate chips or peanut butter) and coconut oil in a small microwave-safe bowl. Microwave on HIGH until melted, about 2 minutes, stirring every 30 seconds.
Dip frozen marshmallows (or strawberries or banana slices) in mixture, letting excess drip off, and place on a parchment paper-lined baking sheet. Let stand until set, 30 seconds to 1 minute. Store leftover shell topping in an airtight container in refrigerator. To reheat, microwave in a microwave-safe bowl on HIGH until smooth and melted, about 30 seconds, stirring every 10 seconds.