01 - Preheat oven to 350°F (175°C). Grease a standard loaf pan with butter or nonstick spray.
02 - In a medium bowl, whisk together flour, baking soda, salt, and pumpkin pie spice until evenly blended.
03 - In a large mixing bowl, beat softened butter with granulated sugar until pale and fluffy.
04 - Add eggs one at a time to the creamed mixture, mixing well after each addition. Stir in pumpkin puree and buttermilk until combined.
05 - Gently fold the dry mixture into the wet ingredients just until no streaks of flour remain. Do not overmix.
06 - Pour batter evenly into the prepared loaf pan and smooth the top. Bake for 55–60 minutes, or until a toothpick inserted in the center emerges clean.
07 - Let loaf cool in the pan for 10 minutes before transferring to a wire rack to cool completely.