5 Whole Star Anise
1 tbsp Coriander Seeds
1 tbsp. Cumin Seeds
1 tbsp. Mustard Seeds
1½ tsp Whole Cloves
4 dried Chiles de Árbol, or 2 tsp. Crushed Red Pepper Flakes
2 Guajillo Chiles, seeds removed
3 tbsp. Toasted Sesame Seeds, divided
¼ cup Ground Sumac
4 tsp. Unsweetened Cocoa Powder
1¼ tsp. Ground Cinnamon
1 tsp. Ground Allspice
1 tsp. Ground Coffee
2 2½-lb. Racks St. Louis–Style Pork Spareribs
Kosher Salt
½ medium Red Onion, thinly sliced
⅓ cup Red Wine Vinegar
2 tsp. Sugar
12oz Kombucha , (about 1½ cups)
4 Garlic Cloves, thinly sliced
1 medium White Onion, cut into 2" pieces
2 medium Oranges, cut into 2" pieces (peel and all), divided
Cilantro Sprigs, (for serving)
Toast star anise, coriander seeds, cumin seeds, mustard seeds, and cloves in a dry small skillet over medium heat, tossing occasionally, until very fragrant and just beginning to darken, about 5 minutes. Transfer to a plate; let cool. Finely grind in spice mill or with mortar and pestle; transfer to a bowl. Finely grind chiles de árbol, guajillo chiles, and half of sesame seeds. Add to ground spices along with sumac, cocoa powder, cinnamon, allspice, coffee, and remaining sesame seeds; mix well.
Season ribs all over with salt (we recommend 1¼ tsp. Diamond Crystal or ¾ tsp. Morton kosher salt per lb.) and sprinkle with ½ cup mole powder, pressing to adhere. Arrange on a rimmed baking sheet and let chill, uncovered, overnight.
Place racks in upper and lower thirds of oven; preheat to 300°. Mix red onion, vinegar, sugar, and a few pinches of salt in a medium bowl; set aside.
Transfer ribs to a deep roasting pan and pour in kombucha. Scatter garlic over and arrange white onion and half of orange pieces around ribs. Cover pan tightly with foil; bake on lower rack until tender but not falling apart, 2½–3 hours.
Remove ribs from oven. Heat broiler. Uncover ribs and broil on upper rack, turning once, until crisp, about 5 minutes.
Transfer ribs to a platter. Skim fat from liquid in pan and discard; drizzle liquid over ribs. Top with drained pickled red onion, cilantro, and remaining orange.