Preheat the oven to 350F degrees.
Grease and flour a 9x13 inch baking pan.
Add the lemon juice to the milk. Allow to sour for at least 5 minutes before using.
In a medium bowl whisk together the flour, cinnamon, baking soda and salt.
In a large bowl beat together the butter and sugars until fluffy (about 2-3 minutes).
Beat in the vanilla and eggs 1 at a time. Then mix in the mashed bananas.
Beat in the flour mixture about 1/3 at a time, alternating with about 1/3 of the milk. Turn off the mixer and scrape down the sides of the bowl as necessary. Only mix the batter until just combined.
Pour the batter into the prepared pan and bake for 40-50 minutes, or until an inserted toothpick comes out clean.
In a large bowl, beat the butter until fluffy. Beat in the cream cheese.
With the mixer on low speed beat in the salt and 2 1/2 cups powdered sugar.
If the frosting isn't quite sweet enough or thick enough, slowly beat in the rest of the powdered sugar. If it's too thick or a little too sweet, mix in the cream.
Frost the cooled cake and slice into pieces.
*Unfrosted cake can be wrapped tightly and frozen for up to 2 months. Thaw in the fridge.
**Store leftovers in an airtight container at room temperature for up to 3 days, or in the fridge if your kitchen is warm.