Preheat your oven to 350°F (175°C) and line an 8x8-inch baking pan with parchment paper, leaving some overhang for easy removal.
In a large mixing bowl, combine the rolled oats, mashed bananas, honey (or maple syrup), almond butter, cinnamon, and salt. Mix well until everything is fully incorporated.
Gently fold in the blueberries, chopped nuts, and chia seeds (if using) until evenly distributed.
Pour the mixture into the prepared baking pan and press it down firmly with a spatula to create an even layer.
Bake in the preheated oven for about 25-30 minutes, or until the edges are golden brown and the center is set.
Allow the bars to cool in the pan for about 10 minutes, then use the parchment paper to lift them out onto a cutting board. Let them cool completely before cutting them into bars.
Store the bars in an airtight container at room temperature for up to a week or in the refrigerator for longer freshness.