Preheat your oven to 325 degrees F. Line 2 large baking sheets with foil and place the ribs on each sheet.
In a small bowl, whisk together the brown sugar, chili powder, smoked paprika, chili powder, garlic powder, onion powder, kosher salt, black pepper, cumin and cayenne pepper.
Taking all but about 1/4 cup of the spice mixture, spread it all over the ribs. Press in where you can, and cover each rack with foil. Place the ribs in the oven and bake for 2 1/2 hours or until the ribs are tender, but not quite falling off the bone.
Once the ribs have baked, remove them from heat and set aside. Preheat your grill to medium-high heat. While the grill is heating up, prepare your glaze. Pour the dripping from your ribs into a medium saucepan and add 1/2 cup of unsalted butter (1 stick). Melt the butter, and then whisk in the remaining 1/4 cup of spice mixture. Cook for about 10 minutes and then remove from heat. Whisk in the red wine vinegar. The sauce will bubble up a little, and that's OK. Transfer the sauce to a small bowl and have a brush handy.
Once your grill is hot, add the ribs and spread on the glaze generously. Flip them after 5 minutes and continue to glaze. Flip them once again after 5 minutes, continuing to glaze. After about 20-25 minutes of flipping every 5 minutes, remove from heat.
Cut the ribs into individual pieces and drizzle with remaining sauce or serve on the side. Enjoy!