Line a 9-inch square pan with wax paper; set aside.
In a large microwave safe dish, melt diary-free butter. Stir in brown sugar, powdered sugar, and peanut butter. Mix well and press into parchment lined pan.
In a medium microwavable bowl, heat chocolate chips and coconut oil for 1 minute. Stir and microwave an additional 30 seconds. Stir until smooth.
Pour approximately 3/4 of the chocolate over the peanut butter crust and spread evenly.
Sprinkle mini marshmallows and chopped peanuts over the melted chocolate.
Drizzle the remaining melted chocolate over the top.
Refrigerate until completely firm, at least 4 hours or overnight.
Pull parchment paper out of pan and place onto a cutting board.
Cut into 16 bars.
Store in an airtight container in the refrigerator for up to 5 days.