• Preheat oven to 350°F. In a medium saucepan, heat the pumpkin puree, cinnamon, and pumpkin pie spice over medium heat. Stir often for about 5–7 minutes.
• Remove from heat and stir in the sugar, brown sugar, and oil. Let sit for 5 minutes to cool before adding the eggs.
• Whisk in the eggs and buttermilk until fully mixed together. After it is completely smooth, fold in the flour, baking powder, baking soda, and salt. Mix just until combined.

Cream Cheese Filling:

• In a separate bowl, beat the softened cream cheese, sugar, egg, vanilla, and flour until completely smooth.
• Grease two 8 1/2 x 4 1/2-inch loaf pans with non-stick cooking spray or butter. Divide half of the pumpkin batter evenly between the two pans.
• Spoon the cream cheese filling evenly over the batter in each pan, dividing it evenly between the two loaves.
• Top with the remaining pumpkin batter, covering the filling as best you can. Take a knife and swirl it through each pan in a zigzag or figure-eight motion to create a marbled effect.

Streusel Topping:

• In a small bowl, add the brown sugar, softened butter, and flour. Using a fork, press together until combined.
• Sprinkle the streusel topping evenly over the batter in both pans. Bake for 48–55 minutes, or until the center is cooked through. Check by inserting a toothpick into the center — it should come out clean or with a few moist crumbs, not wet batter or cream cheese. Tent it with foil. With about 20 minutes of baking time left, lay a piece of foil loosely over the top of each pan. Spray the underside of the foil with non-stick cooking spray first, so the streusel doesn't stick and pull off when you remove it. This keeps the streusel from getting too dark while the center finishes baking.
• Let the pumpkin loaves cool in the pans for 20 minutes, then turn out onto a wire rack. For the cleanest slices, let cool completely (or chill briefly) before cutting. Serve with butter.