Start by heating your oven to 350°F (175°C). Grease your loaf pan with butter or cooking spray. Line the bottom with parchment paper. This helps the bread come out easily later.

Take a medium bowl and add your flour. Stir in the baking soda and the salt. Use a whisk to combine them well. This ensures your bread rises evenly in the oven.

In a large bowl, beat the softened butter and sugar. Use a mixer until the mixture looks fluffy and light. This process adds air to the batter for a better texture.

Add the eggs one at a time to the butter mixture. Beat well after each egg is added. This makes the batter smooth and strong enough to hold the heavy bananas.

Peel your very ripe bananas and put them on a plate. Use a fork to mash them until they are mostly smooth. A few small lumps are perfectly fine for texture.

Stir the mashed bananas into the butter and sugar mixture. Add the sour cream and the vanilla extract. Mix everything until the wet ingredients are fully combined and fragrant.

Slowly add the flour mixture to the wet ingredients. Use a spatula to fold gently. Do not overmix the batter. Stop as soon as you don’t see any more white flour.

Gently fold in the chopped walnuts. These provide a lovely contrast to the soft bread. Ensure they are spread evenly throughout the thick batter so every slice has some.

Pour the batter into your prepared loaf pan. Smooth the top with a spoon. Bake for about 60 minutes. A toothpick inserted in the center should come out clean.

Let the bread rest in the pan for 10 minutes. Then, move it to a wire rack to cool completely. Slicing it while cool prevents the bread from falling apart.