Preheat oven to 350°F. Grease or spray an 8×4-inch loaf pan with nonstick baking spray.
In a medium bowl, whisk together the flour, baking soda, salt, and cinnamon. Set aside.
1¼ cups all-purpose flour, 1 teaspoon baking soda, ½ teaspoon salt, ½ teaspoon ground cinnamon
In a large bowl or stand mixer, cream together the butter and sugar until light and fluffy. Add the eggs, one at a time, mixing until well blended. Stir in the vanilla extract and pumpkin purée until smooth.
½ cup softened butter, 1 cup sugar, 2 large eggs, 1 teaspoon vanilla extract, 1 cup pumpkin purée
On low speed, gradually add the dry ingredient mixture and mix just until combined. Gently fold in the chopped walnuts.
1 cup chopped walnuts
Pour the batter into the prepared loaf pan and smooth the top.
Bake for 45–50 minutes, or until a toothpick inserted in the center comes out clean and the internal temperature reaches about 200°F.
Let the bread cool in the pan for 10 minutes, then remove and place on a wire rack to cool completely.
Slice and enjoy once fully cooled.