Preheat oven to 350 degrees. Line a loaf pan with parchment paper and set aside.
Cream the softened butter and sugars together until light and fluffy. Add the pumpkin, eggs, vanilla and milk.
Add all dry ingredients and mix until smooth
Spread half of the batter into the loaf pan. Drizzle half of the walnut butter on top and swirl into the batter with a knife. Repeat with the remaining batter and walnut butter.
Top with chopped walnuts
Bake 60-70 minutes or until a toothpick inserted into the center comes out clean.