ROLLED BUTTERCREAM FONDANT (allrecipes.com)

Made this with a friend and put it on top of a carrot cake made from a box - delicious! 
Warning: Very sweet!

Rolled Buttercream Fondant


1 cup light corn syrup
1 cup shortening
1/2 teaspoon salt
1 teaspoon clear vanilla extract
2 pounds confectioners' sugar

1. In a large bowl, stir together the shortening and corn syrup. Mix in the salt and vanilla flavoring, then gradually mix in the confectioners' sugar until it is a stiff dough. If you are using a stand mixer, use the dough hook attachment. Otherwise, knead by hand. If the dough is sticky, knead in more confectioners' sugar until it is smooth. Store in an airtight container at room temperature or in the refrigerator.Use food coloring - if you wish to color fondant.
2. To use, roll out on a clean surface that has been dusted with confectioners' sugar until it is 1/8 inch thick or thinner if you can. Drape over frosted and chilled cakes and smooth the sides down, or cut into strips to make bows and other decorations. 

 
 

 Above: Carrot cake with store bought frosting between layers.

Above: Carrot cake with buttercream fondant on top.

Enjoy!