Preheat your oven to 275°F (135°C). Grease a 9x13-inch baking pan with butter and lightly dust with flour.

Mash ripe bananas in a small mixing bowl until smooth. Stir in lemon juice and set aside.

In a medium bowl, whisk together all-purpose flour, baking soda, and salt until evenly mixed.

Cream softened butter and granulated sugar together until light and fluffy, about 3-5 minutes.

Gradually beat in the eggs, one at a time, followed by the vanilla extract.

Alternately mix in the dry ingredients and buttermilk, starting with flour and mixing just until combined.

Folding the mashed banana mixture gently into the batter without deflating it is crucial.

Spread the batter evenly in the prepared baking pan and bake for 1 hour or until a toothpick comes out clean.

Cool the cake in the pan for 10 minutes, then transfer to the freezer for 45 minutes to retain moisture.

Prepare the cream cheese frosting by creaming together butter and cream cheese, then add vanilla and icing sugar.

Once the cake is completely cooled, spread the frosting generously on top.