blue berry banana muffin

Ingredients:-  3 large ripe bananas   , 3/4 cup sugar ,  1/3 cup melted butter   or rifined oil , 1 cup blueberries , 1 teaspoon baking soda  ,  1 teaspoon baking powder  ,  1/2 teaspoon salt , 1 tea spoon white vineger .
1  1/2 cups flour

Directions:

1 )         Mash bananas in a large mixing bowl.

2 )          Add sugar

3 )          Add butter and blueberries.

4 )          Combine dry ingredients and gently stir into banana

               mixture.

5 )          Pour into 12 well-greased muffin cups.

6 )           Bake at 375 degrees for 20 minutes.