Preheat oven and prep pan: Preheat the oven to 350°F and line a 12-cup muffin tin with paper liners or grease it well. This keeps the muffins from sticking and gives you even browning around the edges.

Mash the banana: In a large bowl, mash the ripe banana with a fork until mostly smooth, leaving a few small lumps for texture. A very ripe, spotted banana mashes easier and adds more natural sweetness.

Mix the wet ingredients: Whisk the pumpkin puree, eggs, Greek yogurt, honey and vanilla into the mashed banana until the mixture turns pale orange and fully blended, about 1 minute.

Whisk the dry ingredients: In a separate bowl, whisk together the rolled oats, protein powder, baking powder, baking soda, pumpkin pie spice and salt so the leaveners are evenly distributed before they meet the wet mixture.

Combine wet and dry: Pour the wet mixture into the dry ingredients and fold gently with a spatula just until no dry streaks remain, about 15 strokes. Overmixing at this stage makes the muffins dense instead of light.

Rest the batter: Let the batter sit for 5 minutes so the oats soften and absorb some of the liquid, thickening slightly and making the batter easier to scoop.

Fill the muffin cups: Divide the batter evenly among the 12 muffin cups, filling each about three-quarters full. Sprinkle pumpkin seeds or a few extra oats on top for crunch.

Bake until domed: Bake at 350°F for 20 to 22 minutes, until the tops spring back when pressed lightly and a toothpick inserted in the center comes out clean.

Cool before removing: Let the muffins cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely. This short rest keeps the bottoms from steaming and getting soggy.

Store or serve: Serve the muffins warm or at room temperature, or store them in an airtight container for later. They firm up slightly as they cool, which makes them easier to pack for lunches.