In a large bowl mash the bananas until smooth. In the same mixing bowl, whisk in the melted butter, oil, sugar, eggs, extracts and sour cream until smooth and well combined. Using a spoon or spatula, fold in the dry ingredients to the wet.
Gently remove the cake from the pan using the parchment paper overhang. Cool the cake in the cake pan placed on top of a cooling rack for 20 minutes. Prepare the caramel glaze after the cake has cooled about 30 minutes.
Pour the warm caramel sauce into a bowl with the powdered sugar. Pour in the vanilla extract.Whisk until well combined. Pour the caramel glaze over the cooled banana bread cake. Top the glaze with chopped nuts if desired. Slice and enjoy!