Preheat the oven to 350°F. Grease a 9-by-5-inch loaf pan or an 8-by-6-inch casserole dish, or line the pan with parchment paper.
Weigh and mill 240 grams of soft white wheat berries.
In a medium bowl, whisk together the freshly milled flour, baking powder, baking soda, salt, and pumpkin pie spice.
In a large bowl, whisk together the eggs, pumpkin puree, buttermilk, coconut sugar, melted butter, and vanilla until evenly combined.
Add the dry mixture to the wet mixture. Fold just until no dry flour remains. Fold in the toasted pecans.
Let the batter rest for 10 to 15 minutes so the freshly milled flour can absorb the liquid.
Spread the batter evenly in the prepared pan.
Bake a 9-by-5-inch loaf for approximately 70 minutes, or bake an 8-by-6-inch casserole for approximately 45 minutes. Because ovens vary, check for doneness with a toothpick inserted near the center. It should come out clean or with a few moist crumbs and no wet batter.
Cool in the pan for approximately 15 minutes. Remove the bread from the pan and cool completely on a wire rack before frosting.
Beat the softened cream cheese and butter with the whisk attachment until smooth. Gradually add the powdered sugar and beat until smooth and fluffy. Add cream one tablespoon at a time if the frosting needs to be thinned. Add vanilla if desired.
Spread the frosting over the completely cooled pumpkin bread. Dust with cinnamon before slicing and serving.