Preheat the oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or grease with cooking spray.
In a large mixing bowl, combine the mashed bananas, eggs, Greek yogurt, honey, and vanilla extract. Whisk until smooth and well combined.
In a separate bowl, whisk together the whole wheat flour, vanilla whey protein powder, baking soda, baking powder, ground cinnamon, and salt.
Gradually add the dry ingredients to the wet ingredients, stirring gently until just combined. Do not overmix.
Add the almond milk and melted coconut oil to the batter and fold in until evenly incorporated.
Divide the batter evenly among the 12 muffin cups, filling each about 3/4 full.
Bake for 18 to 20 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Remove the muffins from the oven and allow them to cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.