Preheat oven to 350°. Line either 18 large muffin cups or about 36 minis with paper liners. Spray liners with cooking spray.

In a bowl, combine the flour, sugar, chocolate chips, cocoa, baking powder and salt. In another bowl whisk together the milk, chocolate syrup, sour cream, eggs, oil and vanilla until smooth. Add the wet ingredients to the dry ingredients a little at a time mixing until the batter is just blended. Stir in the mashed bananas.

Fill the muffin papers about 3/4 full and bake for about 15-20 minutes or until pick inserted comes out clean. The minis will cook faster than the regular size muffins. Cool completely.

Enjoy.