Layer peanuts and then vanilla candy coating into the crockpot (I used a 5 quart). Cover. Cook for 1 hour on low temperature without lifting the lid.
After 1 hour, stir the mixture and continue to cook, stirring every 15-20 minutes for another hour (a total of 2 hours).
Meanwhile, line 3 cookie sheets with Silpat mats or line countertop or table with a long piece of parchment paper.
Turn off crockpot. Reserve 1/2 cup M&M's.
When you are ready to scoop, pour remaining M&M's into the crockpot and fold inches.
Working quickly, use a 1 tablespoon scooper to portion out candy from crockpot and onto parchment paper. Make sure candy is not touching. Once entire cookie sheet is scooped (before candy dries) top with 1 M&M and sprinkles.