Sour Cream Chocolate Banana Bread

I got an email yesterday that said, "You HAVE to make this bread. That's an order. I know it probably means a special trip to the store for sour cream but it will be worth it, I promise".  Clearly, my friend knows me well (especially the part about not having sour cream on hand!).  I made a loaf this morning (I always follow orders!) and let me tell you - this bread is wonderful.  Moist, rich, chocolaty goodness.  If you'd like a slice, come now.  I'm pretty sure the kids and I will pound through the rest of the loaf by tomorrow.  And, yes - I like a little coffee in my cream.  Don't judge.
  

1 stick of salted butter, softened to room temp.
1/2 cup sugar
1 egg
2 large ripened bananas mashed ( or 2.5 small bananas)
1 tsp. vanilla
1 cup flour
1 tsp. baking soda
2 Tbl. cocoa powder
1/2 cup of sour cream (I couldn't get to the store, so I used full fat Greek yogurt)
1 cup of mini chocolate chips (I used 3/4 cup of regular chips)
optional 1/2 cup of chopped walnuts

Preheat over to 350 degrees.  Lightly grease a 9×5 loaf pan, or 2 mini pans with non-stick spray.

In a large bowl, cream butter and sugar together. Stir in egg, mashed bananas, sour cream, and vanilla until well blended.  Add baking soda, cocoa, and flour.  Mix everything until well incorporated (about 3 minutes in a Kitchenaid mixer).  Add chocolate chips and nuts (if applicable).

Pour batter into loaf pan(s) and bake for 50 minutes – 1 hr.  Insert a tooth pick into the center of the loaf and check to see if it comes out clean when you pull it out.

Remove from heat and allow bread to rest in the loaf pan for 10 minutes.  Invert the loaf pans onto a cooling rack. Enjoy warm or cold.