Preheat oven to 350 degrees.
Line a 10x10 baking pan with parchment and lightly spray with cooking spray.
In a large microwave proof bowl add in butter and chocolate chips.
Melt together for 30 seconds.
Stir and heat for another 30 seconds.
Stir until well combined.
Mix in brown sugar and granulated sugar.
Pour in vanilla and mix.
Add in eggs one at a time, beating well after each one.
Add in gel coloring.
Using a sifter, sift in flour and cocoa powder. Gently fold in.
Pour batter into prepared pan and bake for 35 minutes.
While the brownies are baking, remove each ghost from their wrappers.
Using an edible black marker, draw two eyes on each ghost and set aside.
Remove brownies from the oven and immediately place 16 white chocolate ghosts evenly apart.
Let them cool for 1 hour before removing them from the pan.
Gently lift up the parchment paper and place the brownies on a flat surface. Using a large knife, cut into 16 squares.