Easy Banana Muffins

Preheat oven to 375*  18 regular muffins
3 ripe bananas
1 cup firmly packed brown sugar
1/2 cup vegetable oil
1 large egg
1 teaspoon vanilla
2 cups self-rising flour
1/2 cup sour cream
Mix bananas, brown sugar, vegetable oil, egg, and vanilla until smooth
Add flour slowly until just mixed; Stir in sour cream
Fill prepared muffin tins 2/3 full
Bake in pre-heated 375* oven 18 to 20 minutes or until toothpick comes out clean when inserted in center