To begin, preheat your oven to 350 and line a 9x9 pan with parchment paper (or spray with non-stick spray).
To a small bowl, add your flour, pumpkin pie spice, baking soda and salt and stir them together.
To a large mixing bowl, add your butter, brown sugar and applesauce and beat together with a mixer till creamy. Add your pumpkin and vanilla and mix in. Add your eggs and milk and mix in briefly, till just combined.
Add your dry ingredients to your wet ingredients and stir them together till you have a smooth, thick batter. Pour into your pan and spread into an even layer along the bottom.
To a small mixing bowl, add your butter, sugar, flour and pumpkin pie spice. Stir together till you have a thick, crumbly mixture. Sprinkle the mixture across the top of your pumpkin coffee cake batter, in one crumbly layer across the top.
Bake in the oven for 35-40 minutes, or till a toothpick inserted comes out clean.
Let cool, then slice and devour!