Preheat oven to 350 degrees. Grease and flour a 9 by 2 inch round cake pan
Mix the bananas, sugar, and brown sugar until combined, continue stirring.
Add the oil, eggs, sour cream, vanilla, and orange zest. Mix until smooth.
In a separate bowl, sift together the flour, baking soda, and salt.
Add dry ingredients to the wet ingredients and mix until combined.
Stir in the chopped walnuts, if using. Pour the batter into the prepared pan and bake for 45 to 50 minutes, until a toothpick inserted in the center comes out clean.
Cool in the pan for 15 minutes, turn out onto a cooling rack, and cool completely.
Infused Cream Cheese Frosting
Mix the cream cheese, butter, and vanilla until just combined. Don’t whip! Add the sugar and mix until smooth.