Preheat the oven to 350°F (175°C) and line a 12-cup muffin tin with paper liners or grease the cups.
In a large mixing bowl, mash the ripe bananas with a fork until smooth.
Add the eggs, honey, unsweetened applesauce, and vanilla extract to the mashed bananas and whisk until well combined.
In a separate bowl, whisk together the whole wheat flour, rolled oats, baking soda, baking powder, ground cinnamon, and salt.
Add the dry ingredients to the wet ingredients and stir gently until just combined.
Fold in the plain Greek yogurt until incorporated, being careful not to overmix.
Divide the batter evenly among the 12 muffin cups, filling each about 3/4 full.
Bake in the preheated oven 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 let them cool in the tin for 5 minutes.
Transfer the muffins to a wire rack to cool completely before serving.