Peel and mash 3 bananas with a fork; set aside.
Melt 2 tablespoons Challenge Spreadable with Avocado in a large saucepan over medium heat. Add oats and cook for about 3 minutes, stirring constantly, until fragrant and toasty.
Add mashed bananas, milk, brown sugar, ground flaxseeds, salt, and cinnamon. Bring to a boil, reduce to a gentle simmer, and cook, stirring every so often, until oats are tender, about 25 minutes. Stir in more milk, to loosen, if desired. Stir in vanilla.
Divide oatmeal among 4 bowls. Slice the remaining 2 bananas and divide over the top of the oatmeal. Top each bowl with a tablespoon each of Challenge Spreadable with Avocado and walnuts. Serve hot.