In a medium size saucepan, add your sugar, water, light corn syrup, green food coloring, and cream of tartar. Mix using a whisk.
Bring your ingredients to a boil while making sure to whisk continually.
Continue to whisk and boil until you reach the temperature of 275°.
Once it has reached optimal temperature, pour your contents onto a small to medium size cookie sheet.
You will want it to be the same height and thinness, so using the back of a spoon or a heat safe spatula, level out your candy.
Allow the candy to cool on your cookie sheet for at least two hours.
While your candy is cooling, prepare your frosting. Add 12 drops of green food coloring to your frosting. You can add more or less depending on your preference. Mix well together.
Add to your piping bag your piping tip, and then your frosting. Cut the tip of your piping bag and allow the tip to fall into the hole and push your frosting down.
Pipe your cupcakes to frost.
If you choose to add your brown sugar to represent the sand, sprinkle that on now.
Once the two hours is up, and your glass candy is ready, break the glass using the back of a spoon. Continue to break until you reached your desired size for each shard of glass.
Stick 3 to 5 pieces of glass to top your cupcake.
Enjoy!