Step 1

Preheat oven to 350°. Lightly coat a 9- x 5-inch loaf pan with nonstick cooking spray; set aside. With a hand mixer, in a bowl, beat butter and sugar until creamy. Add eggs, 1 at a time, and beat about 3 to 5 minutes, until light and fluffy.

Step 2

In a medium bowl, whisk together flour, baking soda and salt. Add to the butter mixture and mix until just combined. Add vanilla, sour cream and bananas; mix to combine. Stir in nuts, if using. Pour into prepared pan.

Step 3

Bake about 1 hour and 10 minutes, or until a toothpick inserted in the center comes out clean. Let rest in pan on a wire rack for 10 minutes, then turn out onto rack to cool completely.