Preheat the oven to 350.
Pour the brownie batter out onto a large sheet pan. You may need to use two sheet pans, the batter should be pretty thin on the pan, about 1/2 inch. Spread with a spatula if necessary to even out.
Bake the brownie batter for 10-15 minutes or until firm. You want them to be dark around the edges.
Allow the brownie bark to cool completely.
Place in freezer for about 10 minutes. This will help the brownie to harden and pop right off the pan
Use your hands or a butter knife to break the brownie into pieces.
Have two small bowls handy. In one, mix the coconut and food coloring.
Spread out onto wax paper or a piece of tin foil for it to dry.
In the second bowl, add powdered sugar, milk, and vanilla.
Mix well.
Drizzle the icing all over the brownie brittle.
Sprinkle the coconut over the icing and lightly press down. This will help the coconut adhere to the brittle.