Preheat the oven to 350℉.
In a bowl, add in the brown sugar, flour, pumpkin spice and the cold butter. Use a pastry cutter or your hands to cut the butter into the ingredients. When finished, place the bowl in the refrigerator until you're ready to use it.
Now, mix together the butter, pumpkin, sugar, eggs and vanilla. In another bowl, add in the flour, baking powder, baking soda, salt and the pumpkin spice. Combine the dry and wet ingredients.
Pour half the batter into the baking pan. Then, remove the crumbles from the fridge and add half in a layer across the batter. Pour the remaining batter on top of the crumbles. Then, finish the coffee cake with the remains crumbles across the top.
Place in the oven and bake 35-40 minutes or until the pumpkin coffee cake is cooked through the center. Allow to cool before serving, enjoy.