Step 1: Preheat your oven to 400°F (200°C) and line a 12-cup muffin tin with paper liners or grease it thoroughly. This initial high temperature helps create that beautiful domed top.
Step 2: In a large bowl, whisk together the all-purpose flour, granulated sugar, light brown sugar, baking powder, baking soda, ground cinnamon, ground nutmeg, ground ginger, ground cloves, and salt. Ensure there are no lumps for a well-combined dry mix.
Step 3: In a separate medium bowl, whisk together the pumpkin puree, vegetable oil, eggs, and vanilla extract until well combined.
Step 4: Pour the wet ingredients into the dry ingredients. Stir gently with a spatula just until combined. Do not overmix; a few lumps are fine. If using streusel, prepare it now by combining the flour, brown sugar, cinnamon, and melted butter until crumbly.
Step 5: Divide the batter evenly among the 12 muffin cups, filling each about two-thirds full. If using streusel, sprinkle it evenly over the top of each muffin.
Step 6: Bake for 5 minutes at 400°F (200°C), then reduce the oven temperature to 375°F (190°C) and continue baking for another 15-20 minutes, or until a wooden skewer inserted into the center of a muffin comes out clean.
Step 7: Let the muffins cool in the muffin tin for 5 minutes before transferring them to a wire rack to cool completely. This prevents them from getting soggy at the bottom.