Step 1

Preheat the oven to 360°F (182°C) and line an 8-inch square metal baking pan with parchment paper.

Step 2

In a large mixing bowl whisk together the dry cake ingredients (flour, spices, baking powder and soda, salt). In a separate bowl, combine the wet ingredients (pumpkin, sugar, maple syrup, oil, milk, vanilla, and vinegar). Don't combine dry and wet just yet.

Step 3

To make the streusel topping, in a small bowl stir together the almond flour, brown sugar, and cinnamon. Add the tablespoon of water and stir with a fork until the mixture looks clumpy and is uniformly moist.

Step 4

To make the batter, pour wet ingredients into dry, and stir until there is no visible dry flour. Transfer the batter to the prepared pan and smooth the top. Sprinkle the streusel mixture on top, and bake for 40 to 45 minutes. The cake is done when a toothpick inserted in the center comes out clean or if the center lightly bounces back when pressed.

Step 5

Let the coffee cake cool in the pan for 15 minutes, then lift out onto a metal rack to cool completely. To make the icing, stir the ingredients together in a bowl, adding another teaspoon of milk if needed. Drizzle on individual slices of coffee cake just before serving.