Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper or a silicone mat.

Mash the bananas in a medium bowl until mostly smooth with just a few small lumps. You want a thick puree.

Stir in the oats until fully coated and evenly mixed. The mixture should be thick and scoopable, not runny.

Fold in the chocolate chips. If using vanilla or a pinch of salt, add them now.

Scoop the dough into 12 mounds (about 1 heaping tablespoon each) on the prepared sheet. Use the back of the spoon to gently flatten to about 1/2-inch thick. They won’t spread much in the oven.

Bake for 12–15 minutes, until the edges look set and the bottoms are lightly golden. They’ll still feel soft—this is normal.

Cool on the sheet for 5 minutes, then move to a rack to finish cooling. They firm up as they cool.