Preheat your oven to 350°F (175°C) and grease three mini muffin pans.

In a large mixing bowl, combine the Devil’s Food Cake Mix, large eggs, canola or vegetable oil, and black food coloring if desired. Blend until smooth, about 2-3 minutes.

Scoop out ½ tablespoon of dough into each greased muffin cup and gently flatten the dough.

Bake for 8-10 minutes or until the edges are set; press an indentation into the center immediately after baking.

Cool the cookie cups for about 5 minutes in the pans, then transfer to a wire rack.

Beat softened butter in a mixing bowl until creamy, then gradually add powdered sugar, vanilla, salt, and milk. Beat until fluffy.

Mix in green food coloring to achieve your desired shade.

Pipe the green buttercream into the cooled cookie cups, filling the indentations.

Decorate each cookie with sprinkles, candy eyeballs, and pretzel sticks.