There are two types of people in this world: the ones that resist baking with pumpkin because it is an annual fad, and the ones that go full-tilt cuhrazy until bars and muffins and cookies and pie tumble out of every shelf in their fridge and pantry when you open the door like a messy teenager closet in a cartoon. And this coffee cake is the world's great unifier: A little different, so you don't need to feel like you're falling into some overdone seasonal hype, and a little different, so it'll go nicely next to the 14 other orange baked goods on your dessert table. See? I've got you. —Kendra Vaculin
Mix flour, baking soda, baking powder, salt, and spices together in a large bowl and set aside.
In a medium bowl, mix pumpkin, brown sugar, oil, syrup, buttermilk, and vanilla until well blended. Add wet mix to dry ingredients and fold to incorporate. This will be the thickest batter of your whole life. You will be very sure you did something wrong, but you did not. Press on with confidence; there is pumpkin cake in your future, by God. Fold until just combined, trying not to overmix.
Next, assemble the crumble. Place butter, flour, brown sugar, 1 tablespoon maple syrup, and cinnamon together in a bowl, cutting the cold butter into the rest with a fork, mixing until small chunks form. Set aside.
Pour half of the batter into a prepared pan that has been well greased. I used a medium-sided bundt pan, which worked out really nicely, but a loaf pan or a small casserole dish situation would also be clutch. After the first half of the batter has been poured, sprinkle the crumble all over the dish, and then top with the remaining batter. This does not have to be perfect. Accept your own shortcomings. Additionally, any cake that smells like this pumpkin magic is automatically a success regardless of how clean your crumble layer is.
Bake cake for 30 minutes, or until a toothpick inserted comes out clean.
Let cake cool while you assemble glaze (whisking milk and remaining 1/4 cup maple syrup into powdered sugar). If using a bundt pan, invert cake onto a wire rack to cool. Drizzle glaze over cake once it has completely cooled. Slice and serve cake to every person you know.