Preheat your oven to 350°F (175°C). Grease a 9x5 inch loaf pan, or alternatively, line it with parchment paper for easy removal.
In a large mixing bowl, combine the all-purpose flour, baking powder, baking soda, salt, cinnamon, nutmeg, ginger, and granulated sugar. Whisk until all dry ingredients are evenly mixed and there are no clumps.
In a separate bowl, whisk together the pumpkin puree, milk, melted butter, egg, and vanilla extract. Stir until the mixture is smooth and well-integrated.
Gradually pour the wet mixture into the bowl containing the dry ingredients. Use a spatula to gently fold the mixtures together just until combined. Be careful not to over-mix; a few lumps are perfectly fine.
In a small bowl, mix the packed brown sugar with pumpkin pie spice, setting it aside for layering.
Take a portion of the dough and pinch off small pieces, about 1-2 inches in size. Roll each piece into a ball between your palms.
In your prepared loaf pan, arrange the dough balls in layers. Between layers, sprinkle some of the brown sugar and pumpkin pie spice mixture. If desired, add a few chopped walnuts in between some layers to introduce a delightful crunch.
After layering all the dough balls, sprinkle any remaining brown sugar and spice mixture generously over the top.
Bake the bread in the preheated oven for 30-35 minutes, or until the top is beautifully golden brown and a toothpick inserted into the center comes out clean.
Once baked, allow the bread to cool in the pan for about 10 minutes. Carefully transfer it to a wire rack to cool completely.
Notes
Serve warm on a rustic wooden board, dust with powdered sugar and drizzle with maple syrup for added sweetness.