Preheat oven to 350.
Grease and flour a 9x13" baking pan. Set aside.
Mash 3 medium bananas in a small bowl. Set aside.
In a medium bowl, whisk together flour, baking soda and cinnamon. Set aside.
Combine milk and lemon juice. Set aside.
In a large bowl, combine butter, sugar, brown sugar, vanilla and eggs. Beat until fluffy.
Alternately add in portions of milk mixture and flour mixture, stirring each to combine.
Fold in mashed bananas.
Transfer batter to prepared pan.
Bake 50-55 minutes or until toothpick inserted in center comes out clean.
Allow to cool for 15 minutes then place in refrigerator for at least 30 minutes before frosting.
Beat cream cheese, butter and vanilla until well blended.
Slowly beat in powdered sugar.
Spread frosting over cake and refrigerate until ready to serve.