1/2 cup (1 stick) butter, at room temperature, plus more for pan
1 cup granulated sugar
2 large eggs
1 1/2 cups unbleached flour
1 teaspoon baking soda
1 teaspoon salt
1 cup mashed very ripe bananas
1/2 cup sour cream
1 teaspoon vanilla extract
1/2-1 cup fresh cranberries
Preheat oven to 350 degrees. Butter a 9-by-5-by-3-inch loaf pan; set aside. In an electric mixer fitted with the paddle attachment, cream butter and sugar until light and fluffy. Add eggs, and beat to incorporate.
In a medium bowl, whisk together flour, baking soda, and salt. Add to the butter mixture, and mix until just combined. Add bananas, sour cream, and vanilla; mix to combine. Stir in cranberries, and pour into prepared pan.
Bake until a cake tester inserted into the center of the cake comes out clean, about 1 hour 10 minutes. Let rest in pan for 10 minutes, then turn out onto a rack to cool.
Adapted from “The Martha Stewart Cookbook: Collected Recipes for Every Day”
Makes 1 large loaf.