1/2 lemon, preferably Meyer lemon, cut into wedges
Preheat the oven to 400°. Poke the cinnamon into the eggplant. Roast the eggplant on a baking sheet until tender, about 50 minutes. Transfer the eggplant to a bowl, cover with plastic wrap and let cool slightly. Discard the cinnamon and peel the eggplant.
In a microwave-safe bowl, cover the raisins with water and microwave at high power until plumped, about 30 seconds. Drain the raisins and transfer them to a blender. Add the roasted eggplant and the olive oil and puree until smooth. Season the puree with sea salt and cayenne.
In a bowl, mix the kosher salt with the water until it is the consistency of moist sand. On a parchment paperlined baking sheet, mound one-fourth of the salt slightly larger than the fish. Lay the fish on the salt and fill its cavity with the bay leaves and lemon wedges. Poke a short skewer into the thickest part of the fish, just behind the head. Pack the remaining kosher salt over and around the fish to enclose it; leave the skewer visible.
Bake the fish for about 35 minutes, until an instant-read thermometer inserted in the skewer hole registers 135°. Let the fish rest for 5 minutes; crack and remove the salt crust. Serve the fish without the skin, with the eggplant puree alongside.