Follow these simple, step-by-step instructions to bake a perfect batch of 3-ingredient banana cookies. The process is forgiving and incredibly quick, making it an ideal recipe for beginner bakers or for when you need a treat in a hurry.

1. Preheat and Prepare: Begin by preheating your oven to 350°F (175°C). This is a crucial first step, as a properly heated oven ensures the cookies cook evenly and in the specified time. Line a large baking sheet with parchment paper or a silicone baking mat. This prevents the cookies from sticking and makes cleanup an absolute breeze. If you don’t have either, you can lightly grease the pan, but parchment paper is highly recommended for the best results.
2. Mash the Bananas: Peel your very ripe bananas and place them in a medium-sized mixing bowl. Using a fork or a potato masher, mash the bananas thoroughly. You can aim for a relatively smooth consistency, but leaving a few small lumps is perfectly fine and adds a nice texture to the final cookie. The goal is to create a wet, puree-like base.
3. Combine the Ingredients: Add the rolled oats directly into the bowl with the mashed bananas. If you are using chocolate chips or another add-in, pour them in as well. Use a spatula or a wooden spoon to mix everything together until just combined. Be careful not to overmix. You only need to stir until all the oats are coated with the banana mixture. The “dough” will be wet, sticky, and not at all like traditional cookie dough.
4. Scoop and Shape: Using a tablespoon or a small cookie scoop, drop rounded mounds of the mixture onto your prepared baking sheet. Space them about 1-2 inches apart. This is a very important step: these cookies will not spread or flatten on their own during baking. Use the back of a spoon or your slightly damp fingers to gently press down on each mound to form a flattened, circular cookie shape, about ½ inch thick. The shape you form them into is the shape they will be when they are done baking.
5. Bake to Perfection: Place the baking sheet in the preheated oven and bake for 15-20 minutes. The exact time will depend on your oven and the size of your cookies. You’ll know they are done when the edges are lightly golden brown and the centers feel set to the touch. They will still be soft when they come out of the oven.
6. Cool Completely: Remove the baking sheet from the oven and let the cookies cool on the pan for 5 minutes. This allows them to firm up slightly, making them easier to handle. After 5 minutes, carefully transfer the cookies to a wire cooling rack to cool completely. Allowing them to cool on a wire rack prevents the bottoms from becoming soggy as steam escapes.