In the bowl of a stand mixer fitted with a paddle attachment, mix the butter and powder sugar on low until blended, then mix on medium for 2 to 3 minutes until fluffy.
Add vanilla and heavy cream and blend one more minute.
Add more cream to get to desired consistency.
Place a small amount of frosting into a small bowl and add green food coloring until the frosting is the color that you want. Spoon into a baggie and set aside.
Add orange food coloring to the remaining frosting until you get the orange color that you want. If you are combining red and yellow go slow with the colors because otherwise you could end up with a color that you do not like by adding too much of one color.
Once you have the decided the colors, frost each cupcake with the orange frosting, then sprinkle with the orange sugar.
Snip the corner of the baggie of green frosting and make vines on the cupcakes.
Stick an unwrapped tootsie roll into the side of the cupcake where you drew the vines.