Preheat the oven to 350º Fahrenheit. Lightly grease a 9x13 inch baking pan. Set aside.
In a large bowl beat the butter and sugar with an electric mixer on medium-high speed until creamy and fluffy. About 4-5 minutes. Add in one egg at a time and blend until fully incorporated.
Add 1 cup of sour cream, mashed bananas, and lemon juice to the batter. Continue to blend on medium speed until until smooth. Sift flour into the batter. Add baking soda, baking powder, and salt and blend until well combined.
Pour the batter into the prepared pan. Bake for 30-35 minutes at 350º Fahrenheit until golden brown on top.
Use a wooden toothpick to check for doneness in the center of the cake. If the toothpick comes out clean remove the cake from the oven. Wait to cool completely.
To make the cream cheese frosting combine cream cheese and ½ cup sour cream in a medium bowl. Sift the powdered sugar into the bowl and beat with an electric mixer until well blended.