Preheat. Preheat the oven to 350°F and grease an 8x4 loaf pan. Set aside.
Mash bananas. Add the bananas to a large mixing bowl and mash until mostly smooth.
Add wet ingredients. Stir in the vegetable oil, egg, vanilla extract, and granulated sugar until well combined.
Add leavening. Mix in the baking soda and salt.
Add dry ingredients. Stir in the flour just until no dry streaks remain. Do not overmix.
Fold in mix-ins. Gently fold in the chocolate chips and oats until evenly distributed.
Bake. Pour the batter into the prepared loaf pan and bake for 50 to 60 minutes, or until a toothpick inserted into the center comes out clean.
Cool. Let cool in the pan for 10 minutes, then transfer to a wire rack. Allow the loaf to rest for about 1 hour before slicing so the chocolate can set.
Serve and enjoy.
Notes
Chocolate options. Use semi-sweet, milk chocolate, or dark chocolate chips for different flavor profiles.
Sweetness adjustment. For a sweeter loaf, replace ½ cup of the granulated sugar with brown sugar.
Oats. Quick oats can be used, but the texture will be softer and less distinct.
Storage. Store in an airtight container at room temperature for 3 to 5 days.