Gather all you ingredients.
Preheat oven to 350.
In a large bowl add flour, baking powder, baking soda, salt, and raisins. Mix around well.
Use a second bowl and add butter, brown sugar, milk, and vanilla. Mix around well.
In a small bowl crack the eggs and whisk around well.
Then add the eggs to your wet mixture. Mix around well.
Peel the bananas and then mash them with a fork on a plate. Add the bananas to your wet mixture and mix around well.
Add the wet mixture into the dry mixture and then mix around well to combine all the ingredients.
Line a muffin pan with muffin liners.
Spoon the batter into the muffin liners and fill to the top.
Put the muffins in the oven and bake for 20 minutes. To check if done insert a toothpick in the center and see if it comes clean.
Let the muffins cool for 10 minutes and then enjoy.