Place 1 cup water and trivet inside instant pot.
Grease the inside of four pin-sized mason jars with cooking spray. Set aside.
In a large bowl, whisk together the flour, sugars, baking soda, salt, and cinnamon.
In a medium bowl, whisk together the eggs, butter, buttermilk, and vanilla.
Make a well in the center of the dry ingredients and mix in the wet ingredients, just until combined. The batter should still be lump with a few dry spots.
Fold in the mashed banana and chocolate chips.
Divide the batter evenly between the four jars.
Wrap the top of each jar with foil.
Gently place the covered mason jars inside the instant pot.
Close the lid and set the pressure release valve to sealing.
Press the manual or pressure cook button and set to 15 minutes.
Natural pressure release.
Gently remove the jars and remove the foil.Â
Let the banana bread cool on a cooling rack until the jars are cool to the touch.
Eat the banana bread directly out of the jars or turn them over and gently wiggle to remove the bread.
Store in the refrigerator up to three days.