Preheat oven to 350F
Combine all dry ingredients, except cocoa powder, in a medium bowl and mix well
Add all wet ingredients and mix until smooth
Transfer a third of the batter to a small mixing bowl and add the cocoa powder to it, then mix well
Fold in chocolate chips or nuts if desired. Optional: if you're a fan of turmeric, add 1 tsp to the remaining 2/3 of the batter and mix until even
Spoon a layer of the pumpkin batter into a loaf pan and smooth out, then a layer of the cocoa batter. Repeat until all of both batters is used (2)
Using a knife and holding it vertically from the pan, swirl the batters together from one end of the pan to the other in wave or infinity motion until they look marbled but not muddied, and tap the pan against the counter to remove an air pockets you've created
Sprinkle with any desired topping and bake for 50 minutes or until a toothpick or knife comes out clean in the center
Cool for 10-15 minutes before removing from loaf pan, and (ideally) cool completely before slicing.
Enjoy!
