Step 1: Preheat your oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan or spray with non-stick baking spray.
Step 2: In a medium bowl, whisk together the flour, baking soda, cinnamon, ginger, nutmeg, cloves, and salt. Set aside.
Step 3: In a large bowl, using an electric mixer, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy, about 2-3 minutes.
Step 4: Beat in the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
Step 5: In a separate small bowl, whisk together the pumpkin puree and buttermilk.
Step 6: Gradually add the dry ingredients to the wet ingredients, alternating with the pumpkin mixture, beginning and ending with the dry ingredients. Mix until just combined. Do not overmix.
Step 7: In a small bowl, combine the flour, granulated sugar, brown sugar, and cinnamon for the streusel. Cut in the cold, cubed butter with a pastry blender or your fingertips until crumbly.
Step 8: Pour the cake batter into the prepared baking pan and spread evenly. Sprinkle the streusel topping evenly over the batter.
Step 9: Bake for 50-60 minutes, or until a wooden skewer inserted into the center comes out clean. If the streusel starts to brown too quickly, you can loosely tent it with foil.
Step 10: Remove the cake from the oven and let it cool completely in the pan on a wire rack before icing. This is crucial for the icing not to melt.
Step 11: While the cake cools, prepare the icing. In a medium bowl, beat together the softened cream cheese and butter until smooth. Gradually add the sifted powdered sugar, mixing until well combined. Stir in the vanilla extract. Add milk or cream, one tablespoon at a time, until the icing reaches a smooth, drizzly consistency.
Step 12: Once the cake is completely cool, drizzle or spread the cream cheese icing over the top. Slice and serve your delicious pumpkin coffee cake streusel icing recipe creation!