Preheat the oven to 350°F (177°C) and grease a 10 inch springform pan. In a medium bowl, combine all of the ingredients for the cinnamon swirl and set it aside.
In another medium bowl, whisk together the flour, baking soda, baking powder, salt and spices and set the dry ingredients aside. In a large bowl, whisk together the eggs, C&H® Dark Brown Sugar, oil, pumpkin puree and vanilla extract until the mixture is completely smooth.
Add the dry ingredients to the wet and whisk just until the last streak of flour is combined. Pour 1/2 of the batter into the prepared pan, top with half of the cinnamon swirl filling, repeat with the rest of the batter and top with the second half of the streusel.
Bake the coffee cake for about 40-50 minutes, until it springs back when you press on it. Allow it to cool in the pan for at least 30 minutes before removing.
While the cake is cooling, combine all the ingredients for the glaze and mix until smooth. When cake is finished cooling, pour over cake and serve.