Preheat oven to 350 degrees.
Whisk together dry ingredients in a mixing bowl. Dump in pumpkin puree, milk, oil, and vanilla and then mix until well incorporated.
Pour into a lightly greases 9x9 pan.
Melt butter in a microwave safe bowl. Add brown sugar, flour, and cinnamon and mix until incorporated. Mix in chopped pecans.
Sprinkle evenly on top of cake batter. Note: You can leave it on the top when cooking, or I prefer to lightly poke it (with a finger- poke, do not stir) into the batter in several places. I like the taste of having the streusel areas within my cake. The texture is so good.
Bake for 30-40 minutes or until toothpick inserted in the middle comes out with just a few moist crumbs.
**Homemade pumpkin pies spice is super easy to make and better than store-bought! See recipe HERE.
Store covered for 2 days, or refrigerate for longer. Can Freeze in an airtight container or bag for up to a month.