- 1½ cups baking mix
- 1 cup (packed) dark brown sugar
- ⅓ cup sour cream or plain yogurt
- ¼ cup (1/2 stick) salted butter
- 2 large eggs
- 1 teaspoon vanilla extract
- 4 large very ripe bananas, mashed (about 1 1/2 cups)
- ½ cup cup chopped bittersweet or semisweet chocolate (optional), (optional)
- ½ cup toasted chopped walnuts, (optional)
Preheat oven to 350°. Lightly coat 8½x4½" loaf pan with nonstick baking spray.
Using an electric mixer on medium-high speed, beat brown sugar, sour cream and butter in a large bowl until light and fluffy, about 4 minutes. Add eggs one at a time, beating to blend after each addition and scraping down sides and bottom of bowl as needed. Add vanilla.
Reduce speed to low, add baking mix, and mix until just combined. Add bananas and mix just until combined. Fold in chocolate and/or walnuts, if using. Scrape batter into prepared pan; smooth top.
Bake bread until a tester inserted into the center comes out clean, 60–65 minutes. Transfer pan to a wire rack and let bread cool in pan 1 hour. Turn out bread and let cool completely (if you can resist) before slicing.