How to Make It
Preheat oven to 350ºF. Lightly coat 2 (12-cup) muffin trays with cooking spray.
Spread walnuts and oats evenly on a rimmed baking sheet. Toast in preheated oven until golden, about 10 minutes, stirring once halfway through cook time. Remove from oven.
Whisk together flour, baking soda, baking powder, salt, and cinnamon in a large bowl. Whisk together eggs, mashed bananas, butter, molasses, honey, yogurt, and vanilla in a medium bowl. Fold banana mixture into flour mixture just until flour is almost incorporated. Fold in toasted walnuts and oats until just combined.
Spoon batter evenly into 20 of the prepared muffin tray cups. Sprinkle tops evenly with turbinado sugar. Bake at 350°F until a wooden pick inserted in centers of muffins comes out clean, about 15 minutes. Remove from oven; let cool 5 to 10 minutes.