Preheat your oven to 350°F (175°C) and prepare a muffin tin with paper liners or cooking spray.
In a spacious bowl, blend the mashed bananas with the plant-based milk, agave nectar (or maple syrup), and pureed apples until smooth.
In a separate bowl, combine the oats, protein powder, baking powder, baking soda, cinnamon, and sea salt.
Slowly incorporate the dry ingredients into the wet mixture, stirring gently until just combined.
If desired, fold in the chopped pecans or dark chocolate chunks.
Spoon the batter into the muffin cups, filling each about two-thirds full.
Bake for 18-20 minutes, or until a toothpick inserted in the center comes out clean.
Let the muffins cool in the tin for about 5 minutes before transferring them to a wire rack to cool completely.