**Preheat the Oven:** Preheat your oven to 300°F.
**Prepare Chocolate Batter:** Sift the flour, cocoa powder, sugar, spices, baking soda, and salt into a bowl. Whisk in the eggs, oil, and water until just combined. Fold in the pumpkin puree until well mixed, then stir in the chocolate chips.
**Prepare Pumpkin Batter:** Sift the flour, sugar, spices, baking soda, and salt into a bowl. Whisk in the eggs, oil, and water until just combined. Fold in the pumpkin puree until well mixed, then stir in the chocolate chips.
**Assemble the Loaf:** Grease a large 9x5 inch loaf pan or two medium 4x8 inch loaf pans. The pans should be almost full, leaving about 1/2 inch of space. Using a cookie scoop, alternate dollops of the chocolate and pumpkin batters in a checkerboard pattern, creating two layers with 9 scoops each. The bottom layer should start and end with the same flavor, while the top layer should alternate so chocolate is on top of pumpkin and vice versa. Using a butter knife, gently swirl the batters together, pressing the knife all the way to the bottom for the best effect. Sprinkle extra chocolate chips on top if desired.
**Bake:** Bake for about 1 hour and 30 minutes, or until a toothpick inserted in the center comes out clean. Oven temperatures vary, so start checking at the hour mark. If using a 4x8 inch metal pan, it takes about 1 hour and 25 minutes. If using a large 9x5 inch loaf pan, the bake time will need to be increased.
**Cool and Serve:** Let the bread cool completely before slicing. Store at room temperature for up to 3 days, tightly wrapped in plastic wrap, or freeze for longer storage.