Prepare your crockpot by lining it with parchment paper.
Add the chocolate chips and white chocolate chips to the crockpot.
Set the crockpot on low heat and cover it.
Allow the chocolate to melt for about 1 hour, stirring occasionally.
Once melted, add in the peanuts and crushed pretzels.
Stir until all ingredients are well combined.
Fold in the mini marshmallows gently.
Pour the mixture onto the prepared parchment paper.
Spread it out evenly and sprinkle with candy decorations if desired.
Let it cool completely at room temperature before breaking into pieces.