Preheat oven to 350 degrees. Line a light-colored loaf pan (8 1/2" x 4 1/2" x 2 3/4” high) with parchment paper then grease with nonstick cooking spray. Set aside.
In a large bowl, mix oil, butter, and sugars until well combined.
Stir in eggs, vanilla, and pumpkin until smooth.
Gently stir in dry ingredients until a uniform batter has formed. Scrape sides to ensure no lumps are present.
Pour prepared batter into pan. Spread it evenly across the top. Sprinkle with pepitas, if desired.
Bake 45-50 minutes or until a toothpick comes out with a few moist crumbs.
Cool 10 minutes before loosening edges and removing loaf from pan. Slice into pieces and serve warm or at room temperature.