Preheat oven to 375°. Spray a loaf pan with cooking spray.
Place avocados in a food processor and pulse until smooth. Transfer to a large bowl. Add butter and sugar to the bowl and mix with a hand mixer until well blended.
Place the bananas, eggs, milk, vinegar, and baking soda to the food processor. Pulse until liquefied.
Pour half of the banana mixture into the butter mixture with 1 cup of flour and mix until just combined. Repeat with the rest of the liquid and flour. Do not overmix!
Pour into prepared pan. Top with chocolate chips and bake about 35 minutes, until it’s browned on the top and a toothpick comes out only with slight crumbs (or clean). Cool at least 10 minutes before slicing.
