Set oven to 350°F (175°C).
Line your muffin tin with paper liners.
This prevents sticking.
Peel and mash bananas in a bowl.
Use a fork for this.
Make sure no large lumps remain.
Beat butter and sugar until fluffy.
Add eggs one at a time.
Mix in mashed bananas and vanilla.
Stir until well combined.
Mix flour, baking soda, cinnamon, and salt.
Do this in a separate bowl.
Whisk them together well.
Add dry ingredients to wet mixture.
Pour in the milk too.
Fold gently with a spatula.
Don't overmix the batter.
Stir in chopped pecans.
Spoon batter into cupcake liners.
Fill each about two-thirds full.
Bake for 18-20 minutes.
Insert a toothpick to check doneness.
It should come out clean.
Remove from oven carefully.
Let cupcakes cool for 5 minutes.
Transfer to a cooling rack.