Preheat the oven to 350?F (177?C). Grease a 9-inch square or 9-inch springform baking pan with nonstick spray. Set aside.

In a medium bowl, whisk the flour, brown sugar, and cinnamon together. Cut in the cold butter using a pastry blender or fork to create clumps and crumbs. Set aside.

In a large bowl, whisk the flour, baking soda, baking powder, salt, cinnamon, nutmeg, cloves, and ginger together until combined.

In a medium bowl, whisk the pumpkin, brown sugar, oil, maple syrup, and milk together until combined. Pour the wet ingredients into the dry ingredients and stir until just combined. Avoid over-mixing; the batter will be very thick.

Spoon/pour the batter into the prepared baking pan and spread to make an even surface. Pour the crumb topping evenly on top and gently press it down into the batter.

Bake the cake for 30-35 minutes. Check for doneness at the 30 minute mark by inserting a toothpick into the center. If clean or with a couple moist crumbs, the cake is done. If wet batter is present, bake for 5 more minutes.

Whisk the icing ingredients together. Add an extra splash of creamer/milk to thin out if desired. Drizzle over warm or cooled cake.

Cover leftover cake tightly and store at room temperature or in the refrigerator for up to 3 days.