Preheat oven to 350 degrees F. Line a muffin tin with paper cups and lightly spray with non-stick spray. Set aside.
In a large bowl mash the bananas and greek yogurt until completely smooth. Stir in the melted butter until smooth.
Add the sugar, egg, vanilla, baking soda, salt and flour and stir until the batter is thick and combined. Fold in the chocolate chips then scoop the batter into the prepared muffin cups, filling a little more than 3/4 of the way full.
Bake for 20 to 22 minutes, or until lightly golden brown. Let cool on a wire rack and enjoy!
Sprinkle a few more chocolate chips on top of the muffin batter before baking for a pretty presentation.