Making your own 4 Ingredient Peanut Butter Banana Bars is a straightforward process. Follow these steps to create this delightful treat:

1. Mash Bananas: In a large mixing bowl, mash the ripe bananas with a fork until smooth.
2. Add Peanut Butter: Stir in the peanut butter until fully combined with the bananas.
3. Incorporate Oats: Gradually add the rolled oats and mix until evenly distributed.
4. Add Vanilla: Pour in the vanilla extract and mix until well blended.
5. Prepare Pan: Line an 8×8 inch baking dish with parchment paper for easy removal.
6. Spread Mixture: Pour the mixture into the prepared dish, spreading it evenly.
7. Chill: Cover the dish and place it in the refrigerator for at least one hour to set.
8. Cut Bars: After chilling, remove the mixture from the dish using the parchment paper. Cut it into square or rectangular bars.

These simple instructions make it effortless to prepare a batch of delightful bars that everyone can enjoy!