Spray a 10 12 cup Bundt pan with cooking spray. In a large bowl heat the chocolate and butter in the microwave on high for 1 minute, stirring once during heating.
Remove and stir until melted and smooth. Add the marshmallows to the mixture. Heat in microwave on high 1 minute longer, or until mixture is smooth.
Add the cereal and peanuts and stir until coated and well combined. It will come together, just give it time.
If you're using them, add in the mini chips last so they won't crush or melt. Press the mixture down into a Bundt pan with fingertips.
Let stand 1 hour to set. In warm weather, you may want to put it in the fridge to set.
When you are ready to serve this, loosen it with a flexible spatula and invert on to a plate. Cut in slice.