Begin by placing both types of peanuts in the bottom of a 5 to 6-quart slow cooker. Layer the semi-sweet chocolate chips and milk chocolate chips evenly over the nuts. Finally, place the broken pieces of white almond bark on the very top. Do not stir the ingredients yet, as the layering helps the chocolate melt evenly without burning.
Cover the crockpot with the lid and set it to the low heat setting. Allow the mixture to cook undisturbed for about 1.5 to 2 hours. It is important to keep the lid on during this time to trap the heat, though you should keep an eye on it to ensure the chocolate on the edges does not get too hot.
Once the chocolate and almond bark have softened and appear melted, remove the lid and stir in the alcohol-free vanilla extract. Use a large wooden spoon or spatula to stir everything together until the peanuts are completely coated and the chocolate mixture is smooth and uniform in color.
Line your countertop or large baking sheets with parchment paper or wax paper. Use a cookie scoop or two spoons to drop small mounds of the chocolate mixture onto the paper. You can make them as large or small as you like, but a tablespoon-sized portion is usually perfect for snacking.
Allow the candy clusters to sit at room temperature for at least 1 hour, or until they are completely firm to the touch. If your kitchen is warm, you can move the trays to a cool area or the refrigerator to speed up the setting process. Once firm, they are ready to be served or packaged.
