Preheat the oven to 350 F (177 C). Lightly grease and line the bottom and long sides of a 9 x 9 inch (23 cm) cake pan with parchment paper.
In a large bowl, whisk together the flour, brown sugar, granulated sugar and ground cinnamon for the streusel topping. Work in the melted butter a little at a time until a sand like texture develops. There will be a few bigger crumbs, but most should be finer, smaller pieces. Place the bowl in the fridge until the coffee cake is ready for topping.
1 cup (120 g) all purpose flour, ½ cup (100 g) light brown sugar, ¼ cup (50 g) granulated sugar, 1 teaspoon ground cinnamon, 6 tablespoons (87 g) unsalted butter, melted
In another bowl whisk the light brown sugar, cinnamon and pumpkin spice together until well combined. Set the cinnamon filling aside for now.
6 tablespoons (75 g) light brown sugar, 1 teaspoon ground cinnamon , 1 teaspoon pumpkin spice
In a medium bowl whisk the all purpose flour, baking powder, baking soda, cinnamon, ginger, nutmeg, cloves and salt together until well combined.
2 cups (240 g) all purpose flour, 2 teaspoon baking powder, ¼ teaspoon baking soda, ½ teaspoon salt, 1 teaspoon ground cinnamon, ½ teaspoon ground ginger, ¼ teaspoon ground nutmeg, ¼ teaspoon ground cloves
In a large mixing bowl, whisk the oil, light brown sugar, sugar, pumpkin puree, eggs, vanilla extract and buttermilk until well combined. Whisk in the dry ingredients until just combined.
½ cup (120 ml) neutral baking oil , ½ cup (100 g) light brown sugar, ½ cup (100 g) granulated sugar, 1 cup (245 g) pumpkin puree, 2 large eggs, room temperature, 2 teaspoons (10 ml) vanilla extract , ½ cup (120 ml) buttermilk, room temperature
Evenly spread half pumpkin cake batter into the prepared pan. Top the pumpkin cake layer with the cinnamon sugar. Repeat with a second layer of pumpkin cake. Top with the streusel.
Bake the coffee cake for 45 - 60 minutes or until a toothpick inserted into the center of the pumpkin crumb cake comes out clean or with a few moist crumbs. Cool the cake pan in the pan for 15 - 20 minutes. Gently lift the coffee cake out of the pan using the parchment paper. Transfer to a serving plate or serve right from the pan. Make the maple glaze by whisking powdered sugar with maple syrup and milk or heavy cream. Top the pumpkin cake coffee cake with the glaze, slice and enjoy.
1 cup (120 g) powdered sugar, 2 tablespoons (30 ml) maple syrup, 1 - 2 tablespoons (15 - 30 ml) milk, as needed