Preheat your oven to 350 degrees F and line two loaf pans with parchment paper. Spray the parchment paper with nonstick spray, and set aside.
Add the potatoes to a large pot and fill with just enough water so that it covers the potatoes. Place the pot over high heat and bring to a boil. Boil the potatoes until tender enough to mash, about 15 minutes. Drain and transfer the potatoes to a large bowl. Using a handheld electric mixer, mash the potatoes until no lumps remain.
To the bowl with the mashed potatoes, add the granulated sugar, brown sugar, eggs, coconut oil, sour cream and vanilla extract. Whisk the ingredients together until thoroughly combined. In a separate bowl, whisk together the flour, baking powder, salt, cinnamon, nutmeg, allspice, ginger, and cloves.Add the dry ingredients to the wet and fold the ingredients together until just combined.
Divide the batter evenly between the two loaf pans and sprinkle each loaf with turbinado sugar. Bake the bread for 1 hour or until the loaves are brown and firm. A toothpick should come out with just a few crumbs.
Transfer the bread to a rack to cool for about 10 minutes in the pan and then turn the loaves out of the pan. Serve immediately or wrap the loaves in plastic wrap until you are ready to serve. Enjoy!