Preheat the oven and prep the pan: Arrange an oven rack in the center of the oven and heat the oven to 350℉. Coat the bottom and sides of the loaf pan with butter or oil. Line the bottom and two longer sides with a piece of parchment paper, leaving an overhang of an inch or two on each side (like handles). Grease the parchment paper, and sprinkle turbinado sugar inside the pan, shaking it to coat the bottom and sides. Set the pan aside. Make the persimmon puree: You will use three of the four persimmons in this step. Prep three persimmons by washing, trimming off the top, peeling, and slicing or dicing, removing seeds if necessary. Transfer to a blender and puree until completely smooth. Measure out 1 cup of puree (256 g) and transfer to a medium bowl. Thoroughly whisk the baking soda into the persimmon and then set aside. This step helps to *thicken* the persimmon mixture. With the fourth persimmon - wash it, trim the top off, and slice it horizontally (the short way), so you have thin slices (1/4 to 1/2 inch thick). Set aside. Mix the dry ingredient: In a large bowl, whisk the flour, cinnamon, ginger, cloves, salt, baking powder, and coconut (if using) to combine. Set aside.
Mix the wet ingredients: Once persimmon mixture has solidified, whisk in the granulated sugar, oil, eggs, orange zest, orange juice, and vanilla until thoroughly combined (there will be bits of persimmon floating around, it will smooth out in the oven).
Mix the wet ingredient: Make a well in the center of the flour mixture, then add the persimmon mixture to the dry ingredients. Whisking from the center of the bowl outward, incorporating the dry ingredients into the wet just until thoroughly combined and no pockets of flour remain.
Fill the pan and bake: Scrape the batter into the prepared pan and smooth the top with an offset spatula. Arrange the remaining peeled and cut persimmon slices on the top of the batter, and sprinkle with turbinado sugar. Bake until the cake has risen, the top is firm to the touch, and a cake tester/toothpick comes out clean, approximately 60 to 75 minutes (or internal temperature of 190-200℉). If it starts to brown too quickly, loosely drape a piece of tin foil over the top of the bread. Let cool & remove from pan: Once baked, allow the cake to cool in the pan for 20 minutes on a wire rack. To remove, use a pairing knife or a small offset spatula to cut in between the cake and pan along the shorter sides to loosen and use the parchment paper to lift the cake out. Place on a wire rack, and allow to cool completely before slicing. The cake can be stored tightly wrapped in plastic wrap at room temperature for three days. Or, the bread can be stored wrapped in plastic wrap and frozen for up to two weeks. Simply thaw overnight at room temperature prior to serving.