Preheat oven to 350 degrees Fahrenheit.
Spray a 9 inch loaf pan with nonstick baking spray.
Pour the milk over the oats in a small bowl and set aside. Let soak for 10 minutes.
While the oats are soaking, mix 1 1/2 cups flour, baking powder, cinnamon, nutmeg, pumpkin spice and salt in a mixing bowl.
Stir in the raisins and walnuts in the dry ingredients.
In a separate bowl whisk the sugar, eggs, melted butter and vanilla together and then add oat mixture.
Stir to blend.
Pour sugar mixture into flour mixture and mix until all ingredients are combined into a moist batter.
Pour batter into loaf pan and spread evenly.
Bake for 35-40 minutes or until a toothpick comes out clean.