Cream butter in the bowl of a stand mixer until soft. Add egg, vanilla and sugar cookie mix, and mix until well combined, scraping down bowl as needed.
Divide dough in half. Roll each piece of dough between two sheets of parchment into rectangles approximately ¼” thick. Place dough with parchment on cookie sheets and chill until firm.
Preheat oven to 350° with rack in top third of the oven. Cut sets of stars making more stars for taller trees, and less stars for smaller trees (use the three smallest cutters). If you want trees the same size, use all five sizes for each tree. Bake for 13 to 17 minutes, until the cookies are starting to turn a golden color on the edges. Cookies should be crisp so they will hold up as decorations.
Frost and decorate the smallest cookie (the top of your tree first) and set aside. Frost and decorate the next smallest and place the first carefully on top of the second, positioning it slightly rotated (do not line up the star arms of the tree). Do this for all the layers. Set tree aside for a few hours to completely harden the frosting, making a secure tree that won’t topple over.
© Pamela's Products, Inc.