Preheat oven to 350 degrees. Grease a 8×4 loaf pan with butter and set aside
In a large mixing bowl, cream together the butter, sugar, eggs and vanilla until well blended and smooth. Stir in the bananas
Add to the bowl the flour, baking soda and salt, mixing until just combined. Add in the sour cream and blend well
Pour batter into prepared loaf pan and bake for 1 hour or until toothpick inserted into the center comes out clean. Allow to cool (if you can bear to wait) and dig in!
Once completely cool, wrap the loaf tightly with plastic wrap and store at room temperature up to 4 days
If you have leftovers (doubt it!), store them tightly wrapped in plastic wrap in the freezer. Not sure for how long, since this has never happened to me, although I’m sure it’ll keep for at least 3 months