Step 1: Grease a 13x9 glass dish with butter.
Step 2: Melt butter in a decently large pan over low heat.
Step 3: Once melted, stir in marshmallows and peanut butter.
Step 4: Stir until the marshmallows are melted and the mixture is smooth and creamy.
Step 5: Remove the pan from heat and stir in Cheerios until they are well coated.
Step 6: Add half of the chocolate chips into this mixture and stir until all ingredients are blended together.
Step 7: Press into the glass dish.
(Tip: I coat my hands with butter when putting the mixture in the pan. This way, the cheerios won't stick to my fingers!)
Step 8: Once pressed evenly, pour the remaining chocolate chips on top of the treats. You can add as many as you like!
Step 9: Let the dessert cool for about 10-15 minutes.