In the bowl of a stand mixer, mix the bananas and sugar until the bananas are mostly smooth (not too chunky). Add the vanilla, sour cream, eggs, and oil. Mix until combined.
In a separate bowl, combine the flour, salt, and baking soda. Add to banana mixture until incorporated. Fold in ½ cup of the chocolate chips.
Spoon muffin batter into prepared muffin tins with paper cups, ⅔ full. Sprinkle remaining ¼ cup chocolate chips on the tops for good looks.
Bake at 400 degrees Fahrenheit for 18 to 20 minutes until golden brown on top and edges.