Preheat your oven to 350°F (175°C). This ensures that your oatmeal cups cook evenly and thoroughly.
Lightly grease a muffin tin with cooking spray or line it with muffin liners to prevent the oatmeal cups from sticking.
In a large mixing bowl, mash the 3 ripe bananas until smooth. You want a creamy texture, as this will be the base of your batter.
Add the almond butter, eggs (or flax eggs), and non-dairy milk to the mashed bananas. Whisk everything together until well combined.
In a separate bowl, combine the rolled oats, sea salt, and ground cinnamon. Stir to ensure the dry ingredients are evenly distributed.
Gradually add the dry mixture to the wet mixture, stirring until just combined. Be careful not to overmix, as this can affect the texture of your oatmeal cups.
Gently fold in the fresh blueberries, reserving a few for topping the cups before baking.
Spoon the oatmeal batter into the prepared muffin tin, filling each cup about ¾ full. Top with additional blueberries for a burst of color and flavor.
Place the muffin tin in the preheated oven and bake for 25-30 minutes, or until the tops are golden brown and a toothpick inserted in the center comes out clean.
Allow the oatmeal cups to cool in the muffin tin for about 5 minutes before transferring them to a wire rack to cool completely. Enjoy warm or at room temperature!