01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners or lightly grease with oil or butter.
02 - In a large bowl, mash the bananas thoroughly. Whisk in eggs, honey or maple syrup, milk, vanilla extract, and melted coconut oil or butter until smooth and well combined.
03 - In a separate medium bowl, whisk together old-fashioned rolled oats, baking powder, ground cinnamon, and salt until evenly distributed.
04 - Pour the dry ingredient mixture into the wet ingredients. Stir gently until just combined, being careful not to overmix. Fold in any optional add-ins such as nuts, chocolate chips, or berries if desired.
05 - Divide the batter evenly among the prepared muffin cups, filling each about 3/4 full. Use a spoon or ice cream scoop for consistent portioning.
06 - Bake for 22 to 25 minutes, or until the centers are set and the tops are lightly golden brown. A toothpick inserted into the center should come out clean.
07 - Allow the oatmeal cups to cool in the pan for 5 minutes before transferring to a wire rack to cool completely.
08 - Serve warm or at room temperature, topped with a dollop of Greek yogurt and additional sliced banana, honey, or nuts if desired.