Preheat the oven to 350ºF and place the rack in the middle of the oven. Cover an 8x8 baking pan or dish with foil and spray with cooking spray or use parchment paper with a 1-inch overhang.
Whisk the eggs, sugar, oil, and water together in a large bowl until smooth. Add in the flour, cocoa powder, and salt and use a spatula to fold the ingredients together.
Pour the batter into the prepared pan and bake for 30 minutes or until a toothpick inserted into the center comes out clean. Remove from the oven, but leave it on, and set on a wire rack to cool.
Spread the coconut flakes in an even layer on a rimmed baking sheet and bake for 3 to 5 minutes, tossing occasionally if needed, until it has turned a golden brown. Set aside to cool.
In a small bowl whisk the powdered sugar, 4 teaspoons of milk, and food coloring together until smooth and fully mixed. If the glaze is too thick add another 1 teaspoon of milk. If the color is to light add another drop of food coloring.
Spread the green icing over the top of the prepared brownies making sure to save about 1/4 of the icing. Sprinkle the toasted coconut flakes on top of the icing and nestle the pumpkins on top, gently pushing them into icing.
Pour the remaining icing into a Ziplock bag and cut off the edge. Pipe some vines around the pumpkins. Let the icing set for about 10 minutes before slicing the brownies.