Mash bananas until combined
Mix mashed bananas, sugar, vanilla, and eggs together.
Add melted butter and melted coconut oil to mixture, mix well!
Add flour, cinnamon, baking powder, and salt to mixture. Mix well until the batter is smooth.
Prepare baking dish with parchment paper
Add banana bread mixture to baking dish. About halfway through the mixture, stop pouring to add a thin layer of cinnamon sugar to the batter. Add another small layer of batter on top, and repeat with the sugar. Repeat to create the swirl!
Add walnuts and leftover cinnamon sugar to the top of batter.
Bake at 350 for 50-55 minutes or until a toothpick comes out clean!