Preheat oven to 325 F degrees.
Pat short ribs dry with a paper towel and set aside.
In a large bowl, add short ribs, salt, pepper and garlic powder and toss to coat - packing on any leftover spices in the bowl onto the short ribs. Set aside.
In a large dutch oven heated over medium high, add olive oil and half of the seasoned short ribs - making sure to sear the fat cap first if any of the pieces have that. Turn pieces as needed until golden brown around the outside. Remove and repeat for the second batch.
Once all the meat is seared, remove it from the dutch oven and add 1 cup of the apple cider and use a spatula to scrape any leftover brown bits on the bottom of the pan.
Next, add carrots, celery, onion, apple and garlic, and tomato paste and stir. After a few minutes of cooking the veggies down, add the rest of the cider - scraping up any bits on the bottom of the pan.
Add short ribs back in and add the beef broth on top followed by the thyme, rosemary, and another pinch of salt. The liquid should be just above the top of the short ribs.
Make sure everything is submerged as possible then place the lid on the crock pot and put the covered pot back in the oven for 2.5-3 hours or until the cut of beef is fall off the bone tender.
Take the Dutch oven out of the oven and remove each short rib. Place the dutch oven back on a burner and heat it to high. Add brown sugar, vinegar and salt and let it boil until reduced and thick; about 20 minutes. If there is a lot of surface fat, remove some of it before serving.