Heat oven to 350°F.
Coat muffin tin with cooking spray and/or liners.
In a bowl, combine flour, sugar, baking powder, baking soda, and salt; whisk to blend. Make a well in center; set aside.
In a bowl, combine bananas, milk, egg, and vanilla.
Pour batter into center of dry ingredients; fold together until combined.
Do not overmix.
Fold in raspberries.
Put batter into muffin tins (about 1/2 full)
Bake 20 minutes or until a toothpick inserted in the center comes out clean.
Cool in pan on a wire rack for 10 minutes.
Remove from pan; cool completely.