Preheat oven to 375. Spray or grease 9x13 glass pan.

In a large bowl, mix together oil and sugars. Use an electric mixer to blend in sour cream and cream cheese. Beat in eggs until well blended. Stir in buttermilk and vanilla.

In a separate bowl, stir together cake flour, baking powder, baking soda, and salt. Mix into wet batter.

Gently fold in bananas, nuts, and oats.

Spread into 9x13 pan. Bake at 375 for 35 minutes. Let cool.

Prepare the Cream Cheese Frosting. To make the frosting, Using electric or stand mixer, blend all ingredients together until smooth.

Frost top of the cake with cream cheese frosting.