Line an 8-inch square dish with parchment paper, leaving extra overhang on both sides for easy removal; spray with nonstick cooking spray. Stir the cereal, oats, and peanuts together in a large mixing bowl; set aside.

In a medium-sized saucepan over medium heat, stir together the brown sugar, butter, honey, corn syrup and salt. Bring to a boil and continue to stir until sugar is dissolved and mixture is smooth. Remove from heat and stir in the vanilla. Pour wet ingredients over the dry ingredients, stirring to coat.

Press mixture evenly into the prepared pan. Refrigerate bars until cool to the touch. Remove bars from the refrigerator and evenly spread peanut butter on top. Chill in the freezer for 10-15 minutes, or until the peanut butter layer is firm.

Run a knife along the edges of the pan to loosen bars. Using the parchment overhang, gently pull granola bar slab out of the pan and onto a cutting board. Cut slab into bars (about 1 inch wide and 4 inches long). Place cut bars into freezer for at least 30 minutes, or until hard.

Line a cookie sheet with parchment or wax paper.

Place chocolate chips and coconut oil into a microwave-safe bowl and heat in the microwave until smooth and melted. Working with 2 or 3 bars at a time (and keeping the rest in the freezer), lift a granola bar with a fork, submerge the bottom half of it into the chocolate, lift it above the chocolate, then use a spoon to ladle the chocolate over the bar. Once coated, gently tap the handle of the fork against the side of the bowl to tap off any excess chocolate, then place onto lined cookie sheet. Repeat with the remaining bars.

Place the cookie sheet of chocolate-coated bars into the freezer until chocolate is set and hardened.

Bars can be individually wrapped in plastic wrap, or stored in an airtight container in the refrigerator for up to one week.