Rub the country style ribs with the spice blend or rib rub, or if not using, sprinkle with salt and pepper. In a slow cooker or the Instant Pot, or a casserole, whisk together ketchup, sugar, vinegar, mustard powder, cayenne, 1 teaspoon salt, and 1/2 teaspoon pepper.

Slow Cooker: Add ribs to the slow cooker and toss with sauce. Arrange ribs, bone side up, in a single row. Cover; cook on high in the slow cooker for about 4 to 6 hours on high, or until tender, or eight to 10 hours on low.

Instant Pot: Add ribs and toss in sauce. Set Instant Pot on high pressure for 20 minutes. When finished, allow to go to a natural release for 10 minutes, then manually release remaining pressure. Remove the Country Ribs.

Oven: Preheat oven to 300 degrees F. Add ribs to the casserole and toss with sauce. Cover and cook until ribs are tender, about 2 1/2 to 3 hours. Check the level of liquid from time to time, and add water if needed.

For all methods, serve ribs drizzled with pan juice. Defat if desired. If sauce is too thin, reduce on the stove top or if using the Instant Pot, in the pot.