This was so much fun to make. I did it with my daughter and I must say I was impressed with the results.
You Need:
1 box cupcake mix
2 tubs of frosting- I got the holiday one so came already colored green
Green food dye
Festive sprinkles
Follow directions in back of box. Once cupcakes cool. Ice. Line in a circle.
Fill empty spots with icing. Add food coloring to make a darker green. Fill a zip lock bag with icing and cut tip.
Fill in not grooved areas with decorative sprinkles. 
Sweet eats!