In a large mixing bowl, combine sugar, shortening and eggs; beat until well mixed.
Add sour cream and marmalade; mix well.
Add remaining ingredients and mix well. Chill dough in the refrigerator for 1/2 hour or until cool.
Meanwhile, preheat oven to 400 degrees and coat 2 baking sheets with cooking spray. Prepare frosting; in a medium mixing bowl, beat all frosting ingredients together, adding orange juice only as needed to make frosting spreadable. Set frosting aside.
Remove dough from refrigerator. Using a teaspoon, drop rounded spoonfuls of dough onto prepared baking sheets.
Bake for 8 to 10 minutes or until lightly browned on edges.