Place the frozen meatballs directly into the crockpot, spreading them out evenly to ensure they cook thoroughly.

Pour the spicy barbecue sauce and grape jelly over the meatballs in the crockpot. Stir gently to thoroughly coat all the meatballs with the sauce mixture. I like to make sure every meatball is well-covered for that perfect flavor in every bite.

Cover the crockpot and cook on high for 2 1/2 to 3 hours. Stir occasionally, if possible, to help the sauce coat the meatballs evenly. The meatballs are done when they're heated through and the sauce is nicely thickened and glossy. If you have extra time, you can also cook on low for 4-5 hours for even deeper flavor.