Preheat your oven to 425°F. Get a muffin pan ready with cupcake liners or just grease it with nonstick cooking spray if you don’t have liners.
In a medium bowl, mix together the dry ingredients: 2 cups whole wheat flour, ½ cup rolled oats, 1 teaspoon cinnamon, 1 teaspoon baking soda, 1 teaspoon baking powder, and ¼ teaspoon salt. Set this bowl aside for now.
In a large bowl, mash the 2 ripe bananas—use a mixer or just a fork like I did. The riper they are, the sweeter your muffins will be!
Add 2 large eggs, ⅓ cup unsweetened applesauce, ⅓ cup milk, ⅓ cup plain Greek yogurt, ¼ cup maple syrup, and 1 teaspoon vanilla extract to the mashed banana bowl. Mix it all together until it’s nice and smooth.
Now, pour the dry ingredients into the wet ingredients and mix until it’s just combined. Don’t overmix here. Note: If you’re using nuts (I’m allergic so I never use them), fold in 1 cup of chopped walnuts or pecans now. Mix until just combined.
Divide the batter into the muffin pan filling each cup all the way to the top—trust me, these muffins puff up so nicely! Sprinkle a little bit of rolled oats on the top of each muffin.
Place in the oven to bake for 5 minutes at 425°F. After that, reduce the heat to 350°F and bake for another 15 minutes, or until a toothpick comes out clean when poked through the center of a muffin. Let them cool for about 5 minutes before transferring them to a cooling rack to cool completely.