Add mini marshmallows and butter to a large microwave proof bowl. Microwave for 1 minute and then stir. Continue to microwave in 30 second increments and stir until melted.
Add Nutella and stir until melted and well combined in melted marshmallows.
Stir in cocoa Rice Krispies
Take small amounts of treats and form into tombstones! (You can make them different sizes or all the same, I would recommend buttering your fingers or else you'll get very sticky!) I like to form mine and place them on parchment paper so they don't stick to anything. Make sure the bottom of the tombstone is very flat so that can stand up straight when you're done.
Let cool and then use melted white chocolate (I use Melts) or white frosting to write on RIP. See my photo above to see how I make a mini piping bag out of a small ziplock bag! Enjoy and Happy Halloween!
NOTE: If you don't want to use Nutella you can simply omit it or add a little cocoa powder to the melted marshmallows to add more chocolate flavor and to keep the tombstones dark!