Preheat the oven to 350F. Grease and line a 9”x5” loaf pan or mini loaf pans with baking spray or parchment paper.
In a bowl, mash the bananas with a fork until it looks like puree and there are no more chunks.
In a large bowl whisk together the sugar and butter until they're combined.
Add the eggs, one at a time, whisking until each one is fully incorporated.
Then add the sour cream and vanilla, whisking until they are completely smooth.
Add in the mashed bananas and whisk until it’s combined.
Fold in the flour, baking powder and salt just until the flour is combined.
Fold in 3/4 of the walnuts and a 3/4 of the chocolate chips.
Pour batter into prepared pan and top with the rest of the chocolate chips and walnuts. Or just fold all together.
Bake for about 60 minutes, or until it passes the toothpick test. Remove from the oven and let it cool in the pan for 30 to 60 minutes. Bake for 30 minutes if using mini loaf pans.