In a large bowl mix all filling ingredients using hand mixer or whisk, and set to side.
In another large bowl mix together egg, sugar, oil, greek yogurt, and vanilla, and using a hand mixer, mix until smooth.
Add bananas and stir to incorporate.
In a small bowl, mix together flour, baking powder, baking soda, and salt.
Gently stir the dry mix to the wet, folding it in and stirring until just combined, don't over mix.
Put about ⅔ of the bread mixture into prepared loaf pan.
Put filling mixture over top, and carefully smooth over with a spatula.
Top with remaining bread mix and smooth over the top.
Bake about 50 minutes, until top is golden, and center is set. If top is getting too brown, and center is not set, tent foil over the top.
Allow bread to cool for 10-15 minutes before turning out on a cooling rack.
Baking times will vary based on the bananas you use and their moisture content. It will also vary by climate, elevation, etc. So keep an eye on the bread rather than the timer.
The toothpick trick will not work well because the cream cheese will never set up completely. Instead, give it a jiggle, and see if the center wiggles much.
Bread will keep at room temp for a week, or in freezer for up to 6 months if packaged appropriately.