3 tablespoons lemon juice
2/3 cup milk
2 large very ripe bananas, mashed or 3 small bananas mashed
1 package butter cake mix
1 teaspoon baking soda
1/2 cup butter, softened
3 eggs at room temperature
1 teaspoon of pure vanilla extract
First preheat oven to 350 degrees. Next grease and flour a 9x13 inch pan. Put 1.5 tablespoons of lemon juice in a measuring cup with 2/3 cup milk. Now set this aside. Next mash your bananas with a fork, adding the remaining 1.5 tablespoons of lemon juice to the bananas as you mash.
Now in a large bowl, combine your cake mix and baking soda and then stir to combine. Next add your bananas, softened butter, milk mixture, eggs and vanilla. Beat at low speed until moistened about 30 seconds. Beat this mixture for 5 minutes and pour this into your prepared pan.
Bake your cake in the oven for 30 to 35 minutes, or until center of cake springs back when lightly tapped.
Frost with your favorite frosting