Bring eggs and butter.to room temperature. Generously coat one 9"x5"x3" loaf pan with non-stick cooking spray. Preheat oven to 325 degrees.
In a small mixing bowl combine 1-1/2 cups flour, 1 teaspoon pumpkin pie spice, 1/2 teaspoon cinnamon, and 1/2 teaspoon baking soda. Set aside.
In a large mixing bowl beat butter with an electric mixer on medium low speed till soft. Add sugar and beat for about 3 minutes or till well combined. Add eggs, one at a time, beating for about a minute after each is added, scraping down sides of bowl as needed. Add vanilla. Turn mixer down to low and gradually add flour mixture alternately with pumpkin puree and sour cream. Adding a little of each to the bowl and mixing just until combined after each addition.
Combine streusel ingredients in a small bowl until well incorporated.
Pour batter into prepared pan and sprinkle with streusel topping. Bake for 60 to 65 minutes or until toothpick inserted into center of loaf comes out clean. Cool in pan for about 10 or 15 minutes then remove from pan and cool completely before slicing.