Heat the peanut butter in a microwave-safe dish for 10-15 seconds, or until it's softened and a bit runny.
Spoon an even layer of peanut butter in each silicone mold. Slightly tap the silicone trays to remove any air bubbles and to make them level.
Make the banana mixture by mashing the ripe banana in a bowl with a fork until creamy. Add the Greek yogurt and mix until well combined.
Spoon an even layer of the banana/yogurt mixture until the mold is filled up. Tap the silicone trays lightly on the counter then place them into the freezer for 4 hours.
Remove from the silicone molds and store these frozen treats layered in parchment in an air-tight sealed container in the freezer. Enjoy!