Spray a 9 x 13 pan with cooking spray and set aside.
In a large saucepan, melt the butter over low heat.
When butter is completely melted, add marshmallows and stir consistently until completely melted.
Take pan off of heat and add Rice Krispies, stirring to combine.
In a small pan, add coconut and cook over low heat, stirring, until golden brown. Remove from heat.
Reserve 1/4 cup of chocolate morsels and coconut. Stir remaining chocolate and coconut into marshmallow mixture.
Press the Rice Krispie Treats into the prepared pan.
Top the treats with the reserved chocolate morsels and coconut and use a sheet of wax paper to press the toppings into the Rice Krispie Treats.
Allow the Rice Krispie Treats to set and cut into squares.