Preheat your oven to 350 degrees Fahrenheit. Line a muffin tin with paper liners or lightly grease each cup. This helps the muffins release easily and keeps cleanup simple after baking is finished.

Place the ripe bananas into a large bowl. Use a fork or potato masher to mash them until mostly smooth. A few small banana pieces are fine because they add extra texture and flavor.

In a medium bowl, whisk together the flour, baking soda, baking powder, salt, and cinnamon. Mixing the dry ingredients first helps everything spread evenly through the batter and gives the muffins better texture.

Add melted butter, brown sugar, eggs, vanilla extract, and milk to the mashed bananas. Stir gently until smooth and fully combined. The mixture should look creamy and smell sweet from the ripe bananas.

Slowly add the dry ingredients into the wet mixture. Stir carefully using a wooden spoon or spatula. Do not overmix the batter because that can make the muffins dense instead of soft and fluffy.

Add chopped walnuts or chocolate chips to the batter. Fold them in gently so they spread evenly throughout the mixture. This simple step adds crunch or sweetness to every delicious bite.

Spoon the batter evenly into the prepared muffin cups. Fill each cup about three-quarters full so the muffins have enough room to rise beautifully while baking in the hot oven.

Place the muffin tin into the preheated oven and bake for about 20 to 22 minutes. The tops should look golden brown, and a toothpick inserted into the center should come out clean.

Remove the muffins carefully from the oven and let them cool for several minutes. Transfer them to a cooling rack before serving. Enjoy them warm with butter or a drizzle of honey.