Preheat oven to 350°F. Spray a 9x5-inch loaf pan with nonstick cooking spray. Set aside
In a medium bowl, whisk together the flour, baking soda, salt, cinnamon, nutmeg, ginger, cloves, and baking powder. Set aside.
In a large bowl using a hand mixer on medium speed, beat together the eggs, sugar, pumpkin, oil, orange juice, molasses, and vanilla until fully combined.
Add the dry ingredients to the wet ingredients. Mix on low speed until the ingredients are just combined.
Place half of the batter into a separate large bowl. Add cocoa powder to the separated half. Stir until just combined.
Add alternating scoops of pumpkin batter and chocolate pumpkin batter to the prepared pan until both of the batters have been used.
Use a skewer or knife to gently swirl the batters together in an s-shaped pattern.
Bake for 75-80 minutes, or until a toothpick inserted in the center comes out mostly clean. (A few crumbs are okay!) Allow the bread to cool before slicing and serving.