For a little extra zing, you can add a tablespoon of apple cider vinegar to the brown sugar mixture. If you prefer a hint of fruitiness, consider adding some thinly sliced apples or pears around the pork in the slow cooker. Another lovely variation is to add a touch of heat with a sprinkle of red pepper flakes in the spice mix. For those watching their sugar intake, you could swap out the brown sugar for a sugar substitute that’s suitable for cooking.