Grab a loaf pan and lightly butter the bottom of the pan.
Get a bowl medium in size, and then begin mashing up your bananas. Using a fork is the best way to mash them.
Once the bananas are mashed, add in the vanilla extract, egg, and butter. Mix this all up well.
Then, add in the sugar, baking soda, and salt into the bowl. Mix this well.
Add in the flour, but only add in about half-cup at a time, and then mix together.
Pour your banana bread batter into your loaf pan. Level the batter across the entire pan.
Cover the loaf pan with a piece of paper towel, and then cover with aluminum foil.
Grab the Instant Pot and pour in a cup of water. Put the trivet inside of the Instant Pot.
Add the loaf pan on top of the trivet. Put the lid on the Instant Pot and seal the valve.
Turn your Instant Pot on to "Manual" high pressure for 50 minutes.
Quick release the pressure once the timer is up.
Remove the loaf pan from the Instant Pot and then allow to cool on a wire rack for 5 or 10 minutes.
Once that time is up, remove the banana bread from the loaf pan. Set back on the wire rack for an additional 5 or 10 minutes.
You can now slice up the banana bread, which should slice up into 8 pieces.