- Line an 8x8x2-inch and a 9x13x2-inch pan with foil. Prepare each brownie mix according to package directions and bake one mix in each pan following directions. Cool in pans. Use edges of foil to lift and transfer brownies to a cutting board. Remove foil. From the 9x13-inch brownie, cut 1-1/2x3-inch rectangles for tombstones. Trim the top corners off of some of the rectangles.
- Combine powdered sugar and a little cocoa powder and sprinkle mixture over the tombstones. Tint small amounts of vanilla icing with black and purple food coloring paste. Place each tinted icing into a sealable plastic bag. Snip a tiny hole in one corner of each bag and squeeze the icing to decorate the tombstones, referring to the photo for suggestions. Lightly sprinkle tombstones again with the powdered sugar and cocoa mixture.
- Frost the top and sides of the 8x8-inch brownie with chocolate icing and sprinkle top with cookie crumbs. Insert about half of a 4-inch length of wooden skewer into the center bottom of three brownie tombstones. Position the skewered-tombstones on the frosted brownie with opposite ends of the skewers. (Place the other tombstones on a platter for people to eat right away!)
- For the grass, place some green food coloring paste and a few drops of water into a small sealable container; stir to mix. Add coconut, seal the container, and toss the mixture to color the coconut. Sprinkle the green coconut around the base of each tombstone on top of the graveyard brownie.