I made these Cookie Monster Cupcakes for my son's first birthday party. As this was the first time I've ever made cupcakes, I wanted to go as simple as possible while keeping with the theme. I was crunched for time because like a mom with true type A personality, I insisted on doing EVERYTHING myself. Ten hours before his party I ended up waving the white flag and using confetti cake mix from a box and ready-made buttercream icing.
I used an entire bottle of blue Wilton food coloring for the 2 containers of icing. The icing seems very resistant to color but slowly darkened while in the fridge. I borrowed a pastry bag and hair tip from my mother-in-law and put a thin layer of "fur" on each cupcake. Don't drive yourself nuts trying to make it look completely even, it looks more realistic a bit messy. I separated 12 Oreo cookies from each other and removed the cream (no I didn't used my tongue haha), then I CAREFULLY cut each Oreo side in half to make his mouth. I suggest using a knife with a serrated edge and use a "saw" motion to avoid cracking the cookies.
Then I took jumbo marshmallows (but medium sized will work well also) and cut them in half with kitchen shears. Then I cut a sliver off the side of the "eye" where they will touch. It looks good aesthetically and they stick together making them less likely to fall off. Once I placed the eyes, I used Wilton ready made black icing in a tube to make the pupils. TIP: DO NOT try to "draw" the pupil by moving the tip in a circular motion (I learned the hard way), just simply place the tip where you would like the center of the pupil to be and squeeze until it's as big as you like.
FINAL STEP: Again using the blue icing and hair tip, pipe more "fur" on his face in between the eyes and mouth, allowing the strands to fall a bit over the cut edge of the Oreo. And PRESTO!!! Enjoy your Cookie Monster Cupcakes!