Preheat the oven to 350°F.
Spray a 9x9-inch glass baking dish with non-stick cooking spray and set aside.
In a medium mixing bowl, whisk together the flour, pumpkin pie spice, cinnamon, baking soda, salt, and baking powder.
In a separate bowl, mix together the eggs, oil, brown sugar, pumpkin puree, vanilla extract, and milk.
Fold the wet ingredients into the dry ingredients and stir gently to combine.
Spread the batter into the prepared baking dish.
In another medium bowl, whisk together the flour, baking powder, brown sugar, and cinnamon.
Cut the butter into small pieces and use a pastry blender or fork to mix the butter into the flour mixture, just until the butter is pea-sized.
Stir in 1 tablespoon of milk or cream until the streusel clumps together just slightly. Sprinkle the streusel over the prepared cake batter.
Bake the coffee cake for 40 to 45 minutes. The coffee cake is done when a toothpick inserted into the center comes out with just a few moist crumbs on it.
Allow the coffee cake to cool before adding the glaze.
Whisk together glaze ingredients in a small bowl. Adjust the amount of milk added to make a nice, thick glaze that can be drizzled. Drizzle over the pumpkin coffee cake.
STEP THIRTEEN: Cut into pieces and serve.