Preheat the oven to 360℉ and line a loaf pan with parchment paper.
In the bowl of a standup mixer, beat the butter, granulated sugar, and brown sugar on medium-high speed until fluffy and significantly lightened in color.
Add the eggs one at a time, mixing after each addition until incorporated. Mix in the vanilla extract.
Add the flour, baking soda, salt, and cinnamon to the bowl of the standup mixer, right on top of the wet ingredients. Mix on low speed until just incorporated.
In a medium-sized mixing bowl, mash the bananas with a fork. I don’t like to mash them too much because I think it’s nice when you come across a chunk or two of bananas in a slice of banana bread.
Add the bananas to the batter and mix until just combined.
Fold in the chopped walnuts.
Transfer the batter to the prepared baking pan and bake in the preheated oven for 50 minutes or until a toothpick inserted into the center of the loaf comes out clean but moist.
Notes
You can also place the loaf in a freezer bag and store it in the freezer for up to 3 months.