For the Streusel:

1. Mix softened butter and brown sugar in a bowl until combined using an electric mixer.
2. Add flour, pumpkin pie spice, and salt, and mix until coarse crumbs form.
3. Chill the streusel in the fridge while preparing the cake batter.

For the Pumpkin Coffee Cake:

1. Preheat the oven to 350°F. Grease a 9×9 inch metal baking pan and line it with parchment paper.
2. In a medium bowl, whisk together flour, pumpkin pie spice, baking soda, and salt. Set aside.
3. Cream softened butter and granulated sugar in a large bowl with an electric mixer.
4. Mix in eggs and vanilla until smooth, then add pumpkin puree and buttermilk and mix until combined.
5. Add dry ingredients to the pumpkin mixture and mix until just combined.
6. Pour the batter into the prepared pan and sprinkle the chilled streusel on top.
7. Bake for 60-70 minutes, or until a toothpick comes out clean. If the top gets too brown, cover loosely with foil.
8. Let the cake cool in the pan on a wire rack.

For the Cream Cheese Drizzle:

1. While the cake cools, mix softened cream cheese and maple syrup in a small bowl until smooth.
2. Sift in powdered sugar gradually, then mix in milk until smooth.
3. Drizzle the cream cheese frosting over the cooled cake before serving. Enjoy!