Preheat your oven to 350°F. Grease and flour a 9x5-inch loaf pan. In a dry skillet over medium heat, toast the walnuts, stirring constantly, until fragrant, about 3-4 minutes. Remove from heat, let cool, then coarsely chop.

In a large mixing bowl, cream together the softened butter and sugar until light and fluffy.

Mash the bananas with a fork until they resemble chunky applesauce. Add the mashed bananas and eggs to the butter mixture, and mix until well combined.

In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients to the wet mixture, stirring just until incorporated.

Stir in the vanilla extract, then fold in the toasted walnuts and raisins. Pour the batter into the prepared loaf pan. Bake for 55-60 minutes, or until a toothpick inserted into the center comes out clean. Let the bread rest in the pan for 10 minutes before transferring to a wire rack to cool completely.