Firstly, mill the flour.
To the flour, add baking powder, baking soda, pumpkin spice, and salt. Then, stir to combine.
To a new Medium mixing bowl, add buttermilk, pumpkin puree, brown sugar, melted butter, eggs, and vanilla. Then, whisk these wet ingredients until smooth.
Then, add the dry ingredients into the wet ingredients, and then stir to combine. It should be a smooth batter. (If you want to add any mix-ins like nuts, chocolate chips, etc then, you can add those here.)
Preheat the oven to 350*F
Allow the batter to sit for about 10-15 minutes while the oven preheats. This allows the bran to soften, and the fresh milled flour to start absorbing the liquid.
Line a 5×9 bread pan with parchment paper. I like to leave a little parchment paper over the top to make it much easier to pull the loaf out of the pan.
Place baking sheet under bread pan incase of any spill overs.
Pour the batter into the lined baking pan.
Bake for 60-70 minutes. If the top starts to get too dark, you can add a piece of foil loosely over the top. Bake until a toothpick comes out clean from the center of the loaf. (Also, cast iron or glass pans can take a bit longer to bake sometimes. )
Allow the loaf to cool in the pan for 15 minutes, then using the parchment paper pull the loaf out, and allow to cool completely (1-2 hours) before slicing.
Lastly, enjoy!