Make the Cinnamon Rolls: In bowl of stand mixer, whisk yeast, 2-1/2 cups flour and granulated sugar until well combined.
Add egg, milk, 5 tablespoons melted butter, maple extract, and at least 4 to 5 drops of orange food coloring. Use dough hook to mix until well combined.
Add remaining 2-1/2 cups flour and knead with dough hook on medium-low speed for 5 minutes. During this time, assess the orange color. You want it to be VERY bright orange before it bakes, as the color will fade as the rolls bake. If necessary, add more orange food coloring as the dough is kneaded.
Grease a large bowl with 1 tablespoon room temperature butter. Transfer dough to work surface and shape into a ball.
Transfer dough to prepared bowl. Cover with plastic wrap and allow to rise at warm room temperature 2 hours or until doubled in size.
Once doubled in size, preheat oven to 350 degrees F. Grease 9 x 13-inch baking pan with 1 tablespoon room temperature butter.
Transfer dough to floured work surface and use rolling pin to roll into 10 x 14-inch rectangle.
Make the Filling: In medium bowl, use a fork to stir together brown sugar, 1/2 cup room temperature butter, cinnamon and at least 5 drops black food coloring until you have a wet sand-like mixture that is deep black. Add more food coloring if necessary to get a rich black color.
Evenly spread the black sugar mixture over the rolled out dough, leaving 1/2-inch space around the perimeter. Sprinkle with 2 tablespoons sprinkles.
Starting at one long edge, tightly roll dough into a log.
Use sharp knife to cut log into 12 even pieces, and transfer pieces to prepared baking pan. Cover pan with clean kitchen towel and let rise 10 minutes.
One rolls are slight risen again, transfer pan to center rack of oven and bake 23 minutes.
While the rolls are baking, make the Frosting: In small bowl, whisk powdered sugar, milk and 3 to 4 drops of green food coloring until well combined. Again, you want this to be BRIGHT green, so add more food coloring if necessary. Cut the marshmallows in half lengthwise.
After rolls are done baking, remove from oven and let stand 5 minutes. Then, evenly drizzle the green frosting over the rolls.
Place 4 marshmallow halves on each roll to resemble teeth (optional: use red food coloring to add "blood" to the teeth). Add two candy eyeballs to each roll and sprinkle all rolls with more sprinkles.