Creating Blueberry Banana Muffins is simple if you follow these easy steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and line a muffin tin with paper liners or grease it lightly.
2. Mix Wet Ingredients: In a large mixing bowl, combine the mashed bananas, melted butter, sugar, egg, and vanilla extract. Mix well until everything is incorporated.
3. Add Dry Ingredients: Sprinkle the baking soda and salt over the mixture, then gently fold in the flour. Be careful not to overmix; a few lumps are okay.
4. Incorporate Blueberries: Carefully fold in the blueberries, making sure they are evenly distributed throughout the batter.
5. Fill Muffin Cups: Spoon the batter into the prepared muffin tin, filling each cup about 2/3 full.
6. Bake: Place the muffin tin in the preheated oven and bake for 20-25 minutes or until a toothpick inserted into the center comes out clean.
7. Cool: Once done, remove the muffins from the oven and let them cool in the tin for about 10 minutes before transferring them to a wire rack to cool completely.

Following these steps will ensure that you create the most delicious Blueberry Banana Muffins that are sure to impress.