Place a rack in the center of your oven and preheat the oven to 350 degrees F. Line an 8x4-inch loaf pan with parchment paper so that the paper overhangs the two longer sides like handles. Coat the parchment paper with nonstick spray.
To prepare the cream cheese filling, beat or whisk together the cream cheese, sugar, Greek yogurt, flour, and egg in a medium mixing bowl. Set aside.
Prepare the banana bread batter, mash the bananas until mostly smooth in a large mixing bowl (double-check that you have the right amount or your banana bread may be too moist or too dry).
Whisk in the egg, yogurt, maple syrup, and oil. (If you're using coconut oil and it resolidifies, microwave the bowl for a few seconds to melt it). Then, stir in the brown sugar and vanilla.
In a separate bowl, combine the all-purpose flour, whole wheat flour, baking soda, cinnamon, nutmeg, and salt.
Pour the dry ingredients into the wet ingredients, and gently stir until the flour disappears. Don't overmix!
Pour 1/3 of the banana bread batter into the pan. With two spoons, dollop the cream cheese filling and the remaining banana bread batter alternately over the top to create a batter "mosaic" (you may have more than one layer of the batters; just keep varying it up).
To swirl, insert a butter knife halfway into the batter. Drag it through the batter first vertically a few times (spacing apart each "drag"), then horizontally. Don't stress over this part: no two swirls are alike, and that’s the beauty of this bread!
Bake the cream cheese banana bread for 55 to 70 minutes, until a thin knife inserted in the center comes out without any banana bread batter sticking to it. Check at the 40-minute mark, then periodically after. If the bread starts to brown too much at the corners before it’s baked through, tent it with foil. The most foolproof way to know if banana bread is done is to use an instant read thermometer. When it reaches 200 to 205 degrees F at the center, it is cooked through.
Place the pan on a wire rack and let cool for 15 minutes. Remove the bread from the pan using the “handles” and set it on the rack to finish cooling completely. Slice and enjoy!
Notes
*If using coconut oil, be sure all of the ingredients are at room temperature and the coconut oil has cooled completed to room temperature, or it will resolidify when it touches the cold ingredients.
To bake as muffins (you'll have around 12): Place paper liners in muffins wells and coat with nonstick spray and dollop the batter as directed. Bake at 350 degrees F for 18 to 22 minutes.
TO STORE: Cream cheese banana bread may be stored for several hours, covered, at room temperature. Otherwise, due to the cream cheese, I recommend storing cream cheese banana bread in the refrigerator for up to 5 days.
TO FREEZE: Tightly wrap the banana bread in plastic, then store it in a freezer bag for up to three months. Let thaw overnight in the fridge before serving.