Preheat the oven to 350°F (175°C). Grease the baking dish lightly or line it with parchment paper.

In a large mixing bowl, combine brownie mix, eggs, and oil according to package instructions. Stir until just mixed.

Pour the mixture into the prepared baking dish and smooth out the top with a spatula.

Bake for 25-30 minutes until edges look set and center is slightly soft. A toothpick should come out with a few moist crumbs.

Cool the brownies in the pan for 10-15 minutes, then slice into squares.

Dollop white frosting onto each brownie and stick the chocolate cookie tombstones into the frosting.

Add gummy worms around the tombstones for decoration.

Serve the Graveyard Brownies on a spooky platter.