I don't think the crock pot is malfunctioning. The recipe was poorly written and, honestly, today's slow cookers are more powerful than the ones of yesterday.
Remember, your bigger pot also has more energy (so that it can cook more food).
You should put some water (not a lot) on the bottom so the breast doesn't stick (after all, it doesn't have a layer of skin to protect it) and you don't want the sugar in the BBQ sauce to burn on the direct heat. Here is a sample recipe for turkey breast in a slow cooker that uses a bit of liquid http://www.cookingchanneltv.com/recipes/kelsey-nixon/turkey-roast-dip-with-melted-gruyere-recipe/index.html
Once your breast has an internal temp of 165 - 170 degrees, you want to remove it. You need to pay attention to your meat thermometer -- not what the recipe says. 8-9 hours is simply too long for a single layer of skinless breasts on a direct heat surface with no liquid.
As for the clusters, here's a warning from one online receipe
"One word of caution. While this popular crockpot candy recipe has been around for many years, it was originally written at a time when the old slow cookers cooked at a much lower temperature than they do today. Unless you're still using one of the older ones, don't think you can dump everything in and then just leave it unattended for 3 hours on low.
While all slow cookers vary and you might get away with it, there is also a strong risk that you will end up with nuts and chocolate that tastes, and are, burned with the newer cookers. Even though I do still use my 70-something Crockpot slow cooker for this recipe, I still stir it out of an abundance of caution."
Again, the crockpot is not defective. Today's crockpots simply are more powerful than the ones of yesterday. Use a meat thermometer and you'll find your way back to perfect meats. And, keep stirring your chocolate!
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