Preheat your oven to 350°F. Line a baking sheet with parchment paper or a silicone mat.
Toast the nuts and seeds: In a dry skillet over medium heat, add the almonds, pumpkin seeds, and sunflower seeds. Toss or stir frequently for 3-4 minutes until the pepitas start to pop and the almonds smell warm and toasty. Pour onto a plate to cool.
Make the oat flour: Add 1/2 cup of the rolled oats to your food processor. Pulse for about 20 seconds until it looks like a coarse flour. Add the remaining 1 cup of whole oats and pulse just once or twice to combine.
Blend the wet base: Add the pitted dates, banana, almond butter, salt, and vanilla to the food processor. Process for 30-45 seconds until the dates are broken down into a smooth, sticky paste. You may need to scrape down the sides once.
Combine everything: Add the cooled toasted nuts and seeds, chia seeds, and chocolate chips (if using). Pulse 5-6 times until just combined. You want the mix-ins evenly distributed but still in distinct pieces.
Scoop and shape: Using a 2-tablespoon scoop or a heaping spoonful, portion out the dough. Roll into balls and place on the prepared baking sheet about 2 inches apart. Flatten each ball to about 1/2-inch thickness. Wet your hands slightly if the dough is too sticky.
Bake at 350°F for 12-14 minutes. The edges should be golden brown and the center should still look slightly soft. They will firm up as they cool.
Finish and cool: Immediately after removing from the oven, sprinkle a few flakes of finishing salt over the tops. Let the cookies cool on the baking sheet for 10 minutes, then transfer to a wire rack to cool completely.