In a large bowl, combine the cake mix, sugar, and orange zest. Whisk to combine. Add orange juice, canola oil, vanilla extract and eggs. Blend with the mixer on low speed for one minute, then speed it up to medium and beat for 2 more minutes.

Fill cupcake papers about 1/2 to 2/3 full. Bake at 350F until golden in color and a toothpick test comes out clean, about 22-25 minutes.

Cool in the pan for 10 minutes then transfer to a cooling rack to cool completely.

For the frosting: Place the butter in a large mixing bowl. Add 4 cups of sugar, then 1/4 cup of the juice and the zest. Beat until smooth and creamy.

Gradually add the remaining sugar, 1 cup at a time, until icing is thick enough to be of good spreading consistency (I added 6 cups total). Add more orange juice as needed.   Use and store at room temperature. (Don’t refrigerate and it will last in a covered container for about three days.)