Start by preheating your oven to 350 degrees F and lining an 8x8" baking pan with parchment paper or greasing it well with butter, oil, or cooking spray.
Prepare the flax eggs by whisking together the flaxseed meal and water in a small bowl. Prepare the vegan buttermilk by combining non-dairy milk and apple cider vinegar in a measuring cup. Let both rest for at least 5 minutes.
½ cup vegan buttermilk, 2 flax eggs
While the replacement eggs and buttermilk are resting, prepare the streusel by mixing together the flour, brown sugar, chopped pecans, pumpkin spice and melted vegan butter using your hands, a fork or pastry cutter. Set aside.
½ cup light brown sugar, ¼ cup all-purpose flour, ½ cup pecans, chopped, 1 teaspoon pumpkin spice, 3 tablespoons 40g vegan butter
For the cinnamon sugar layer, in a small bowl whisk together the cinnamon and dark brown sugar. Set aside.
3 tablespoons dark brown sugar, 1 tablespoon cinnamon
In a medium bowl whisk together the flour, baking powder, baking soda, salt, and spices.
2 cups all-purpose flour, 1 teaspoon baking powder, ½ teaspoon baking soda, ½ teaspoon salt, 2 teaspoons ground cinnamon, ¼ teaspoon ground ginger, ½ teaspoon ground nutmeg, ¼ teaspoon ground cloves, ⅛ teaspoon all spice
In a large bowl, whisk together the light brown sugar, granulated sugar, flax eggs, pumpkin purée, melted coconut oil, and vegan buttermilk.
½ cup light brown sugar, ½ cup granulated sugar, 1 cup pumpkin puree, ½ cup coconut oil, 2 flax eggs, ½ cup vegan buttermilk
Pour the dry ingredients into the wet ingredients and fold to mix until just combined/you don't see any streaks of flour.
Pour half of the pumpkin cake batter into the prepared baking dish and top with the cinnamon sugar. Gently pour and spread the remaining batter over top. Spread the pecan streusel over top.
Bake for 40 minutes, or until a toothpick comes out clean. If you notice the streusel getting very dark, feel free to tent the coffee cake with aluminum foil.
Remove from the oven and allow to cool for at least 15 minutes.
OPTIONAL: While the coffee cake is cooling, make the maple vanilla glaze by whisking together confectioners' sugar, maple syrup, non-dairy milk, and vanilla.
1 cup powdered sugar, 1 tablespoon non-dairy milk, 1 tablespoon maple syrup, ½ teaspoon vanilla
Drizzle the maple vanilla glaze over the cake then slice into 9 pieces and serve immediately. Enjoy alone, with coffee or tea, or ice cream!