Slice the brownies into squares.
Using green decorating icing with a round tip, add pumpkin vines (or squiggles) with green icing to the top of each brownie.
Crumble crushed Oreos on top of the green icing.
Break or cut a Milano Cookie in half.
Using black decorating icing with a round tip, pipe the letters R.I.P. with black icing onto the front of the cookie.
Pipe black icing onto the cut end of the Milano Cookie.
Press the "gravestone" into the corner of the brownie.
Add a dab of green icing to the bottom of a candy pumpkin and set it in place on the grave.
And that's it! They're ready to serve for a fun Halloween treat!