Orange Buttercream Frosting on Chocolate Cupcakes

Homemade orange buttercream frosting. Yum!

0.5 cup butter, softened
Zest from 1/3 to 1/2 a regular sized orange (wash it first)
3 cups powdered sugar (more if you need it to be thicker)
1.5 tsp vanilla extract
6 TBL orange juice concentrate (More if you need it thinner)

[chocolate cupcakes from box mix]