Prepare a 9×13″ pan by lining with foil or parchment paper. Lightly grease the paper with softened butter. Set aside.
Brown the butter: heat butter in a medium-sized pot over medium-high heat until melted. Continue cooking, stirring occasionally until butter is dark golden brown and has nutty aroma. (You may need to reduce temperature to prevent burning.)
Pour in marshmallows and stir until completely melted and incorporated into the butter. Remove from heat and add in vanilla extract, stirring until combined. Pour in cereal and stir until all cereal is evenly coated.
Pour cereal mixture into prepared pan. Using a teacup or measuring cup with butter spread on the outside, press cereal mixture into pan evenly. Let cool.
Heat chocolate chips and coconut oil in microwave for 30 seconds (or in a double boiler), stirring until completely melted. Dip half of each treat in chocolate, allowing excess to drip off. Place on parchment-lined cookie sheet. Place cookie sheet in freezer for 20 minutes or until set. Store in airtight container. Note: chocolate will be “tacky” to the touch if left at room temperature.)