Preheat oven to 350 degrees F (175 degrees C). Grease 12 muffin cups or line with paper muffin liners.
In a large bowl, combine flour, baking soda, baking powder and salt. In a separate bowl, cream together the sugar and oil. Stir in eggs and mashed bananas until well blended.
Add banana mixture to flour mixture; stir just to moisten. Spoon batter into prepared muffin cups.
Bake in preheated oven for 18 to 20 minutes, or until a toothpick inserted into center of a muffin comes out clean.