Heat the oven to 350°F (175°C). Grease a 9 x 5-inch loaf pan and, if desired, line it with parchment so the finished loaf is easy to lift out.

Whisk the flour, baking soda, salt, cinnamon, nutmeg, and cloves together in a medium bowl until the spices are evenly distributed.

In a separate large bowl, whisk the eggs and sugar. Add the pumpkin purée, oil, and water, then mix until smooth.

Add the dry ingredients to the pumpkin mixture and stir just until no visible streaks of flour remain. Do not overmix.

Spread about half of the pumpkin batter into the prepared loaf pan. Spoon or gently spread the Nutella over the batter.

Add the remaining pumpkin batter over the Nutella layer. Run a thin knife through the batter in a few loose figure-eight motions to create chocolate ribbons without blending them away.

Bake for 55–60 minutes, or until a toothpick inserted into the pumpkin portion comes out clean or with only a few moist crumbs. A toothpick inserted directly into Nutella may be chocolate-coated.

Cool the loaf in the pan for about 10–15 minutes, then transfer it to a wire rack. Let it cool for at least 30 minutes before slicing so the crumb can set.