Prepare the Icing: In the bowl of a stand mixer, beat the butter on medium-high speed with the paddle attachment until fluffy, or about 5 minutes. Turn the mixer speed to low and slowly add the powdered sugar and beat until fully incorporated. Mix in the vanilla and food coloring. If the mixture is too thick, add heavy cream 1 teaspoon at a time until the desired thickness is achieved. You'll want the icing to be thick enough to hold its shape but still soft. Refrigerate until ready to use; just bring to room temperature before decorating.

Preheat oven to 400 degrees Fahrenheit (even if your cake mix or cake recipe has a lower temperature). Line 2 standard 12 cup cupcake pans or muffin tins with cupcake liners. Place a mini Chips Ahoy cookie in the bottom of each liner.

In a large bowl, prepare cake mix according to package instructions - add the eggs, water, and oil to the dry ingredients and beat just until incorporated.

Fill each of the cupcake liners 3/4 full; this is about 3 tablespoons of batter in each liner. Bake at 400 degrees for the first 5 minutes, then reduce the temperature to 350 degrees for the remaining cooking time.

Cool on a wire rack until the cupcakes are room temperature.

Using a sharp, small paring knife, cut a large half-circle shape out of the top of the cupcake (see photos above) for Cookie Monster's mouth.

Using a grass piping tip, pipe the frosting in an erratic pattern to resemble Cookie Monster's wild furry look. Keep a paper towel nearby to periodically wipe the tip clean, so it doesn't clog.

Place two candy eyeballs ( they don't have to perfectly align because Cookie Monster has crazy eyes) and fill the mouth with Cookie Crisp cereal or mini Chips Ahoy cookies.

Note: These are best eaten shortly after they are decorated because the cookies do get a little chewy as they sit.