Spray the insert of your slow cooker with cooking spray (if desired, to prevent sticking).

Slice the kielbasa into thin-rounds, about ½-inch thick, and add it to the slow cooker. Set aside momentarily.

To a medium bowl, add the bbq sauce, cranberry sauce, pineapple preserves, and whisk or stir to combine. Pour this mixture over the kielbasa in the slow cooker and stir to combine and coat evenly.

Sprinkle the pineapple tidbits and cranberries over the top, stir to combine, and place the lid on the slow cooker.

Slow cook on HIGH heat setting for 3-4 hours, or on LOW for 5-6 hours. Slow Cooking Tips - It doesn't matter with this recipe if you cook on high or low heat setting. It's important to remember that all ingredients in this recipe have already been cooked, so you're not actually "cooking" anything. Rather, you're warming the food and allowing the sauce to come together and thicken. You can toss and stir the food a few times during slow cooking, but resist the urge to constantly lift the lid and "check on" the progress since valuable heat will escape. If your sauce is looking a little thin, remove the lid for the last 1 hour of cooking, give or take. Like all slow cooker recipes, the exact cooking time will depend on your slow cooker and its heat output. Some are very fierce, some aren't. Use your judgment for evaluating doneness.

I like to serve this directly from the slow cooker with toothpicks. This also has the added benefit of keeping the food warm, even if you shut the heat off. If your slow cooker has a "keep warm" setting, you can try it. Or you can transfer it to a serving bowl and serve it that way if you don't mind it cooling off and being served at room temp.