Preheat the oven to 325°F. Line two sheet pans with parchment paper.
In a large bowl, using a wooden spoon, combine the banana, nut butter, maple syrup, cinnamon, and vanilla and mix until the batter is smooth, about 1 minute.
Add the oats, chia seeds, coconut, dried fruit, and chopped nuts and mix until just combined, 30 seconds to 1 minute. The dough will be sticky and stiff.
Divide the dough with a heaping ¼-cup measure into 12 portions and roll into balls.
Place the balls on the lined sheet pans and lightly flatten them using your palm or a measuring cup to form a cookie. If they are sticking, cover the balls with parchment paper before flattening them.
Bake until the cookies are almost completely firm and lightly browned, 15 to 18 minutes, rotating the sheet pans front to back halfway through. Let the cookies cool.