- Pour chex cereal into a large microwavable bowl. Set aside.  
- In a separate microwavable bowl, microwave brown sugar, butter, and corn syrup for 1 minute. Stir until smooth. (Microwave for another 30 seconds if needed) 
- Stir in baking soda. 
- Pour caramel mixture over the cereal and stir to evenly coat. 
- Microwave cereal mixture for 2 minutes, stirring after every minute. 
- Spread onto a cookie sheet lined with waxed or parchment paper. Allow to sit for about 10 minutes. 
- Break into pieces. 
- Evenly sprinkle peanut butter cups and marshmallows over the top of the cereal. 
- In a small microwavable bowl, add caramel bits and cream. Microwave for 1 minute, or until it can be stirred smooth.  
- Use a spoon to drizzle caramel evenly over the top of the cereal. 
- Microwave milk chocolate in 30 second increments, stirring after each, until smooth. (Mine takes 1 to 1.5 minutes)  
- Using a spoon drizzle the chocolate over the cereal mixture. 
- Microwave white chocolate in 30 second increments, stirring after each, until smooth. (Mine takes 1.5 minutes)  
- Using a spoon drizzle the white chocolate over the cereal mixture. 
- Sprinkle coarse sea salt over the top while the caramel, and chocolates are still wet.  
- Allow chocolate to set until hardened. (Place in the fridge for a quicker set) 
-  Break apart and store in airtight container.