Mix tomato paste, vinegar, onion flakes, yellow mustard, molasses, garlic, olive oil, and liquid smoke in a bowl to create a thick paste. Stir brown sugar, kosher salt, cumin, chipotle pepper, paprika, black pepper, garlic powder, mustard powder, and cayenne pepper into tomato paste mixture.
Place pork shoulder into a slow cooker and add paste mixture.
Cook on High for 4 hours. Shred pork with 2 forks and remove bone. Reduce heat to Low and continue cooking for 1 to 2 more hours.
If you're looking for more smoke flavor, you can probably just keep adding liquid smoke until it's enough for your taste without it really changing the recipe too much.
If you are keeping it simmering longer, put it on 'keep warm' or your lowest heat setting. Because of the amount of sugar and molasses, if you are not careful, this recipe will burn very easily, so keep an extra wary eye on it.
Try using a liner in your slow cooker for easier cleanup.
Per Serving: 224 calories;8.4 g fat;
17.4 g carbohydrates;
19.9 g protein;
53 mg cholesterol;
1252 mg sodium.