In a large bowl, mash the bananas well. Add the flour, oil, water, cinnamon, vanilla, baking soda, and vinegar. Stir well to create a uniform batter. It will be slightly thicker than traditional pancake batter.
Heat avocado oil (enough to cover bottom of pan) in a cast iron skillet on medium heat. Pour about ¼ cup of batter into pan. Use the back of spoon to spread batter evenly. Repeat with rest of batter.
Let top of pancakes begin to bubble and the edges to dry (about 3-4 minutes), then flip and cook well on the other side.