Prepare the Crumble: In a mixing bowl, combine your crumble ingredients, ensuring the butter is cut in until the mixture resembles coarse crumbs. Cover it and refrigerate for at least 30 minutes.

Make Dry Mixture: In a separate bowl, whisk together the flour, salt, baking powder, and pumpkin spice until evenly combined.

Combine Wet Ingredients: In a large mixing bowl, whisk the eggs until fluffy. Gradually add in the sugar, butter, sour cream, pumpkin puree, and vanilla extract until smooth.

Mix Ingredients: Gently fold the dry mixture into the wet ingredients until just combined.

Prepare Cream Cheese Filling: In another bowl, beat the cream cheese until smooth. Gradually mix in the powdered sugar and an egg until well blended.

Layer Cake in Pan: Preheat your oven to 350°F (175°C) and grease a springform pan. Pour half of the batter into the prepared pan, dollop the cream cheese filling over, top with remaining batter, and sprinkle the chilled crumble over everything.

Bake: Place the pan in the preheated oven and bake for 40-45 minutes until a toothpick comes out clean.

Cool and Serve: Once baked, allow to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.