Heat your oven to 350Spray a 9X9 pan with vegetable spray.
For the Crumble Topping: combine the brown sugar, cinnamon, pinch of salt, and vegan butter in a bowl. Stir to combine. Add the flour and stir until combined. Set aside.
For the coffee cake: in a large bowl cream together the 3/4 cup of vegan butter and 1 cup of sugar. You can use a spoon here, but stir vigorously until light and fluffy. Add the plant-based milk, ground flax meal, cornstarch, and apple cider vinegar. Stir to combine.
In a medium size bowl combine the flour, baking powder, baking soda and salt. Stir to combine. Add the flour mixture to the milk mixture. Stir until just combined.
Pour the batter into your prepared baking dish. Evenly distribute the crumble topping across the batter. Sprinkle the top with pumpkin seeds. Bake for about 25 - 30 minutes, until a toothpick inserted in the middle of the cake comes out clean. The crumble topping should be nice and golden brown as well.
When done, remove from the oven and allow to cool slightly before serving.