Preheat the oven to 325F. Prepare a 9x5 large loaf pan. Butter all sides of the pan and sprinkle flour on top. Move the flour around until all sides of the pan are coated.
In a medium bowl, add flour, baking soda, and salt. Set aside.
In a large bowl, whisk together egg, sugar, and oil until well combined.
In the large bowl with the wet ingredients, add the banana, milk, and vanilla. For a smooth banana bread, mash the bananas in a separate bowl. For a chunkier banana bread, add the bananas whole and mash them in the batter bowl. Stir until fully incorporated.
Add the dry ingredients to the wet ingredients in the large bowl. Stir well.
Now, make the cheesecake filling. In the bowl of the stand mixer or in a large bowl using a hand mixer, beat the cream cheese and sugar together until smooth. Then add the egg and vanilla, beat again. Lastly, add the flour and stir until just combined.
In your prepared loaf pan, pour in half of the banana bread batter. Evenly spread the cheesecake filling on top of the batter. Then pour the remaining banana bread batter on top.
Bake for 60-75 minutes until a inserted toothpick comes out clean. Let cool for 5-10 minutes and serve!