Start by adding both types of peanuts to the bottom of a 5 or 6 quart slow cooker. Layer the semi-sweet chocolate chips on top of the peanuts, followed by the milk chocolate chips. Finally, place the broken pieces of white almond bark over the top of the chocolate layers. Do not stir the ingredients yet, as layering helps the heat distribute evenly.
Cover the slow cooker with the lid and set it to the low heat setting. It is very important to use the low setting to prevent the chocolate from scorching. Let the mixture sit undisturbed for about one hour.
After one hour, remove the lid and stir the mixture thoroughly with a heavy wooden spoon or heat-resistant spatula. Everything should be starting to melt together into a glossy, thick consistency. Replace the lid and cook for another 30 to 60 minutes, stirring every 15 minutes until the mixture is completely smooth.
Once the candy is fully melted and smooth, turn off the slow cooker and stir in the alcohol-free vanilla extract. Allow the mixture to sit for a few minutes so it is not boiling hot, then stir in half of your Christmas sprinkles if you want them mixed throughout the candy.
Line your countertop or large baking sheets with parchment paper or wax paper. Use a cookie scoop or a tablespoon to drop mounds of the chocolate peanut mixture onto the paper. While the candy is still wet, top each cluster with the remaining festive sprinkles.
Let the candy sit at room temperature for at least 2 hours or until it is completely firm and set. If your kitchen is warm, you can move the sheets to a cool garage or refrigerator to speed up the process.
