Mix together rub ingredients.
Spread rub evenly over both sides of rib racks.
Stand ribs on their side and wrap around the sides of the slow cooker.
Mix together sauce ingredients, leaving out the cornstarch, water and gochujang.
Pour 1 cup of of the sauce into the slow cooker.
Cover and cook on low for 8 hours or until ribs are tender.
Meanwhile, pour remaining sauce into a sauce pan; bring to a boil.
Add gochujang to sauce pan.
Mix together the cornstarch and water.
Pour cornstarch mixture into the boiling sauce.
Reduce heat to medium and simmer until sauce thickens.
When ribs are done, preheat the broiler.
Place ribs on a foiled lined baking sheet and broil until they start to sizzle.
Brush on a thick layer of the sauce and broil again until sticky.
Serve remaining on the side for dipping.