Line a 13x9 pan with wax paper and set aside.
Lightly toast your coconut by spreading it evenly on a cookie sheet and baking at 350F for 8-10 minutes, stopping halfway through to stir the coconut so it bakes evenly (be careful to watch your coconut carefully, it can over-brown quite quickly, you want the coconut to be slightly browned on the edges but not entirely browned. This may take longer than 10 minutes depending on your oven).
Once coconut is toasted, set aside.
In large saucepan, melt together butter, brown sugar, heavy cream, and corn syrup on medium-low heat, stirring constantly with a wooden spoon until butter is completely melted.
Increase heat to medium-high and, stirring constantly, bring to a boil.
Continue to stir for 2 minutes while mixture boils, then reduce heat to lowest setting and continue to stir until mixture is no longer bubbling.
Add marshmallows, stirring until marshmallows are completely melted.
Remove from heat and stir in coconut and mix well, then add cereal and stir until well-combined and cereal/coconut are evenly coated.
Spread evenly into prepared 13x9 pan and allow to set until completely cooled.
Lift cereal bars out of pan and cut into even pieces.
Prepare chocolate by melting chocolate chips and shortening in microwave on 20-second increments until completely melted.
Once melted, dip the bottom of each rice krispie square in chocolate and set on wax paper to harden. Drizzle with chocolate. (The chocolate will harden fastest if you place it in the refrigerator for about 20 minutes).